fix: remove duplicate docker socket mount from PR workflow

The runner already passes through its own docker socket mount to job
containers. Specifying it again in the workflow causes a duplicate
mount point error.

.gitea/workflows/pr.yml

@@ -39,7 +39,6 @@ jobs:
       options: --user root
       volumes:
         - /apps:/apps
-        - /var/run/docker.sock:/var/run/docker.sock
 
     steps:
       - name: Checkout code