staging/{web,graphql}: Migrate rp0 to target from the static backend to their elastic backend counterparts

That moves the http backends to target the one in the staging cluster:

• webapp: backend webapp-postgresql.internal.staging.swh.network (that's an ingress plugged to the web service in the elastic cluster)
• graphql: backend webapp.staging.swh.network (that's another ingress plugged to the graphql service in the elastic cluster)

Manually adapted 'til it worked.

web:

• https://webapp.staging.swh.network/

graphql:

• https://webapp.staging.swh.network/graphql/
• https://graphql.staging.swh.network/

octo-diff rp0 (adapts the http backend for webapp and graphql)

*******************************************
  File[/etc/varnish/includes/01_graphql.vcl] =>
   parameters =>
     content =>
      @@ -7,5 +7,5 @@
       backend graphql
       {
      -    .host = "graphql.internal.staging.swh.network";
      +    .host = "webapp.staging.swh.network";
           .port = "80";
       }
*******************************************
  File[/etc/varnish/includes/01_webapp.vcl] =>
   parameters =>
     content =>
      @@ -7,5 +7,5 @@
       backend webapp
       {
      -    .host = "webapp.internal.staging.swh.network";
      -    .port = "9080";
      +    .host = "webapp-postgresql.internal.staging.swh.network";
      +    .port = "80";
       }
*******************************************
  Profile::Varnish::Vcl_include[graphql] =>
   parameters =>
     content =>
      @@ -7,5 +7,5 @@
       backend graphql
       {
      -    .host = "graphql.internal.staging.swh.network";
      +    .host = "webapp.staging.swh.network";
           .port = "80";
       }
*******************************************
  Profile::Varnish::Vcl_include[webapp] =>
   parameters =>
     content =>
      @@ -7,5 +7,5 @@
       backend webapp
       {
      -    .host = "webapp.internal.staging.swh.network";
      -    .port = "9080";
      +    .host = "webapp-postgresql.internal.staging.swh.network";
      +    .port = "80";
       }
*******************************************
  Profile::Varnish::Vhost[graphql.staging.swh.network] =>
   parameters =>
     backend_http_host =>
      - graphql.internal.staging.swh.network
      + webapp.staging.swh.network
*******************************************
  Profile::Varnish::Vhost[webapp.staging.swh.network] =>
   parameters =>
     backend_http_host =>
      - webapp.internal.staging.swh.network
      + webapp-postgresql.internal.staging.swh.network
     backend_http_port =>
      - 9080
      + 80
*******************************************
  Varnish::Vcl[/etc/varnish/includes/01_graphql.vcl] =>
   parameters =>
     content =>
      @@ -7,5 +7,5 @@
       backend graphql
       {
      -    .host = "graphql.internal.staging.swh.network";
      +    .host = "webapp.staging.swh.network";
           .port = "80";
       }
*******************************************
  Varnish::Vcl[/etc/varnish/includes/01_webapp.vcl] =>
   parameters =>
     content =>
      @@ -7,5 +7,5 @@
       backend webapp
       {
      -    .host = "webapp.internal.staging.swh.network";
      -    .port = "9080";
      +    .host = "webapp-postgresql.internal.staging.swh.network";
      +    .port = "80";
       }
*******************************************
*** End octocatalog-diff on rp0.internal.staging.swh.network

octo-diff pergamon (drop old dns record)

*** Running octocatalog-diff on host pergamon.softwareheritage.org
I, [2023-10-20T12:07:06.462061 #3880044]  INFO -- : Catalogs compiled for pergamon.softwareheritage.org
W, [2023-10-20T12:07:08.349685 #3880044]  WARN -- : Resource File[/tmp/ocd-ipc-20231020-3880044-fnph3l/ocd-builddir-20231020-3880046-mikiq2/routes.yaml] appears to depend on catalog compilation directory. Suppressed from results.
W, [2023-10-20T12:07:08.349746 #3880044]  WARN -- : Resource File[/tmp/ocd-ipc-20231020-3880044-fnph3l/ocd-builddir-20231020-3880045-mikiq2/routes.yaml] appears to depend on catalog compilation directory. Suppressed from results.
W, [2023-10-20T12:07:08.349877 #3880044]  WARN -- : Resource key Ini_setting[puppetdbserver_urls] parameters => path may depend on catalog compilation directory, but there may be differences. This is included in results for now, but please verify.
W, [2023-10-20T12:07:08.349893 #3880044]  WARN -- : Resource key Ini_setting[puppetdbserver_urls] parameters => path appears to depend on catalog compilation directory. Suppressed from results.
W, [2023-10-20T12:07:08.349939 #3880044]  WARN -- : Resource key Ini_setting[soft_write_failure] parameters => path may depend on catalog compilation directory, but there may be differences. This is included in results for now, but please verify.
W, [2023-10-20T12:07:08.349961 #3880044]  WARN -- : Resource key Ini_setting[soft_write_failure] parameters => path appears to depend on catalog compilation directory. Suppressed from results.
I, [2023-10-20T12:07:08.350123 #3880044]  INFO -- : Diffs computed for pergamon.softwareheritage.org
diff origin/production/pergamon.softwareheritage.org current/pergamon.softwareheritage.org
*******************************************
  File[/etc/bind/keys/local-update] =>
   parameters =>
     content =>
      @@ -2,4 +2,4 @@
       key local-update {
        algorithm hmac-sha256;
      - secret "YcTJluRZjNmQKAFh3fvcHNS1N3TXzn9BNe3/L7gHzTXDetSOT4luh/v23sVFsyWn9K7VfhQGIcbAlIREAV6V+g==";
      + secret "IUNrs9pxRw2Phy9+4M6W8IVDgxp5cw88Y8m9eobKlJ3v2oO5Bcdd3k1iklmDDZFLMEZXBZnllxtL7K/HYl8tVg==";
       };
*******************************************
  File[/etc/bind/rndc.key] =>
   parameters =>
     content =>
      @@ -2,4 +2,4 @@
       key rndc-key {
        algorithm hmac-md5;
      - secret "6ZE8s0eBhIy46+EflHFKMD/RCZqwAANs62ddUpAjeC396wBvqE0kOciQmUYgSOSGyVdmx7VguyTPnpoQjlSAig==";
      + secret "hMG9ONH7cG28aOmQp77zUAv7HOf9sGk4cLMnJSMrJ7o7uSix7qFukaSRB670BCyMrSx3ExpdddgMcxJf57UXow==";
       };
*******************************************
- Resource_record[staging-webapp/A+PTR]
*******************************************
- Resource_record[staging-webapp/A]
*******************************************
*** End octocatalog-diff on pergamon.softwareheritage.org

Refs. swh/infra/sysadm-environment#5095 (closed)