fix: set buildx logger limit to 4 MiB, env.BUILDKIT_STEP_LOG_MAX_SIZE=4000000

This PR increases the log limit to 4 MiB (from 2 MiB), getting by the warnings [output clipped, log limit 2MiB reached]

.gitlab-ci.yml

@@ -206,7 +206,7 @@ status:pending:
       done
     - docker context create context
     - docker context use context
-    - docker buildx create --name builder --driver docker-container --bootstrap --use context
+    - docker buildx create --name builder --driver docker-container --driver-opt env.BUILDKIT_STEP_LOG_MAX_SIZE=4000000 --bootstrap --use context
   artifacts:
     paths:
       - build.log