Add NO_PROXY=dind to container env

The Docker CLI inside the job container routes through Squid when
HTTP_PROXY is set, which can't resolve the 'dind' service container
hostname. Bypass the proxy for dind connections.

Author: arr2036

.github/workflows/ci-multi-server-tests.yml

@@ -179,6 +179,7 @@ jobs:
         --memory-swap -1
       env:
         DOCKER_HOST: tcp://dind:2375
+        NO_PROXY: dind
 
     steps: