ci: skip Docker Hub login and push for PR/Dependabot runs

Co-authored-by: beevelop <6891349+beevelop@users.noreply.github.com>

Author: Copilot

.github/workflows/docker.yml

@@ -14,6 +14,9 @@ jobs:
   main:
     runs-on: ubuntu-latest
     timeout-minutes: 30
+    env:
+      # Docker Hub credentials are not available for pull requests and Dependabot runs
+      publish: ${{ github.event_name != 'pull_request' && github.actor != 'dependabot[bot]' }}
     steps:
       - name: Check out the repo
         uses: actions/checkout@v7
@@ -33,6 +36,7 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v4
       - name: Login to Docker Hub
+        if: env.publish == 'true'
         uses: docker/login-action@v4.6.0
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
@@ -48,8 +52,9 @@ jobs:
         id: docker_build
         uses: docker/build-push-action@v7
         with:
-          platforms: ${{ env.platforms }}
-          push: ${{ github.event_name != 'pull_request' }}
+          platforms: ${{ env.publish == 'true' && env.platforms || 'linux/amd64' }}
+          push: ${{ env.publish == 'true' }}
+          load: ${{ env.publish != 'true' }}
           tags: ${{ steps.docker_meta.outputs.tags }}
           labels: ${{ steps.docker_meta.outputs.labels }}
           cache-from: type=local,src=${{ github.workspace }}/cache