Bump max connections for the postgresql server to 200

The current limit got exceeded when deploying the new scrubber checker on staging.

Related to T4102

Test Plan

$SWH_PUPPET_ENVIRONMENT_HOME/bin/octocatalog-diff --octocatalog-diff-args --no-truncate-details --to staging db1.internal.staging.swh.network
Found host db1.internal.staging.swh.network
WARN     -> Environment "staging-add-prometheus-metrics" contained non-word characters, correcting name to staging_add_prometheus_metrics
WARN     -> Environment "staging-bullseye-rabbitmq-plugin" contained non-word characters, correcting name to staging_bullseye_rabbitmq_plugin
WARN     -> Environment "staging-check-journal-client" contained non-word characters, correcting name to staging_check_journal_client
WARN     -> Environment "staging-check-journal-client-2nd-implementation" contained non-word characters, correcting name to staging_check_journal_client_2nd_implementation
WARN     -> Environment "staging-check-journal-client-first-implem" contained non-word characters, correcting name to staging_check_journal_client_first_implem
WARN     -> Environment "staging-pin" contained non-word characters, correcting name to staging_pin
Cloning into '/tmp/swh-ocd.cZDlekEB/environments/production/data/private'...
done.
Cloning into '/tmp/swh-ocd.cZDlekEB/environments/staging/data/private'...
done.
*** Running octocatalog-diff on host db1.internal.staging.swh.network
I, [2022-04-19T15:32:08.226764 #411475]  INFO -- : Catalogs compiled for db1.internal.staging.swh.network
I, [2022-04-19T15:32:08.585119 #411475]  INFO -- : Diffs computed for db1.internal.staging.swh.network
diff origin/production/db1.internal.staging.swh.network current/db1.internal.staging.swh.network
*******************************************
  Postgresql::Server::Config_entry[max_connections] =>
   parameters =>
     value =>
      - 100
      + 200
*******************************************
  Postgresql_conf[max_connections] =>
   parameters =>
     value =>
      - 100
      + 200
*******************************************
*** End octocatalog-diff on db1.internal.staging.swh.network

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Migrated from D7596 (view on Phabricator)