chore: remove committed vendor/modcache archives, add to .gitignore

Remove obsolete Drone CI config. Added to .gitignore.

.golangci.yaml was already removed from next branch.

Co-authored-by: user <user@Mac.lan guest wan>
Reviewed-on: #37
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>

.gitignore

@@ -3,6 +3,8 @@
 *.tmp
 *.dockerimage
 /vendor
+vendor.tzst
+modcache.tzst
 
 # Stale files
 .drone.yml