CI: bump Docker GitHub Actions (#75, #76, #77, #78)

- docker/login-action v3 → v4
- docker/setup-qemu-action v3 → v4
- docker/setup-buildx-action v3 → v4
- docker/build-push-action v6 → v7

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: f3l1x

.github/workflows/docker.yml

@@ -77,20 +77,20 @@ jobs:
         uses: actions/checkout@v6
 
       - name: Set up QEMU
-        uses: docker/setup-qemu-action@v3
+        uses: docker/setup-qemu-action@v4
 
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@v4
 
       - name: Login to DockerHub
         if: github.event_name == 'push' && github.ref == 'refs/heads/master'
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
       - name: Build image for testing (linux/amd64)
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@v7
         with:
           context: ${{ matrix.context }}
           file: ${{ matrix.dockerfile }}
@@ -114,7 +114,7 @@ jobs:
 
       - name: Build and push to registry
         if: github.event_name == 'push' && github.ref == 'refs/heads/master'
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@v7
         with:
           context: ${{ matrix.context }}
           file: ${{ matrix.dockerfile }}