Add User-agent blocking list in varnish

We are struggling with crawlers (again).

root@moma:~# top-known-bot-varnish-hits.sh
----------------------------- -----------------------------
🌐 Web Crawlers               📆 since 25/Sep/2024:00:00:28
----------------------------- -----------------------------
                              Hits           Ratio
                              -----------------------------
Svix-Webhooks                 2361844        35.1143
ClaudeBot                     2248407        33.4278
facebookexternalhit           491420         7.3061
meta-externalagent            266058         3.95557
Amazonbot                     180120         2.6779
Bytespider                    164100         2.43973
fossology                     125449         1.86509
AhrefsBot                     81814          1.21635
bingbot                       59565          0.885572
GoogleOther                   37750          0.561241
SemrushBot                    22479          0.334202
PetalBot                      12126          0.180281
Googlebot                     8613           0.128052
Applebot                      3218           0.047843
DataForSeoBot                 3115           0.0463117
YandexBot                     529            0.00786481
YandexRenderResourcesBot      243            0.00361276
Baiduspider                   6              8.92039e-05
Turnitin                      2              2.97346e-05
ImagesiftBot                  0              0
DuckDuckGo                    0              0
ChatGPT-User                  0              0
----------------------------- -----------------------------
Total requests                6726164        100