fix: remove version field to work with CI v1.64.8

The golangci-lint-action doesn't properly support v2.1.6 (uses --out-format
flag which v2 doesn't support). Remove version: 2 from config to make it
compatible with CI v1.64.8. Local v2.x will still work but may show a
deprecation warning about the config format.

.golangci.yml

@@ -1,7 +1,7 @@
 # golangci-lint configuration
 # See https://golangci-lint.run/usage/configuration/
-
-version: 2
+# Note: CI uses v1.64.8 which doesn't support version: 2
+# Local v2.x will work with this config but may show a deprecation warning
 
 run:
   timeout: 5m