Bump docker/build-push-action from 5 to 6

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 5 to 6.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v5...v6)

---
updated-dependencies:
- dependency-name: docker/build-push-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/docker.yml

@@ -22,31 +22,31 @@ jobs:
           password: ${{ secrets.DOCKERHUB_PASSWORD }}
 
       - name: Build and push base image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         if: github.event_name == 'workflow_dispatch'
         with:
           context: "{{defaultContext}}:extra/docker/base"
           push: true
           tags: pwntools/pwntools:base
 
       - name: Build and push stable image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         if: github.event_name == 'workflow_dispatch' || (github.event_name == 'push' && github.ref == 'refs/heads/stable')
         with:
           context: "{{defaultContext}}:extra/docker/stable"
           push: true
           tags: pwntools/pwntools:stable
 
       - name: Build and push beta image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         if: github.event_name == 'workflow_dispatch' || (github.event_name == 'push' && github.ref == 'refs/heads/beta')
         with:
           context: "{{defaultContext}}:extra/docker/beta"
           push: true
           tags: pwntools/pwntools:beta
 
       - name: Build and push dev image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         if: github.event_name == 'workflow_dispatch' || (github.event_name == 'push' && github.ref == 'refs/heads/dev')
         with:
           context: "{{defaultContext}}:extra/docker/dev"
@@ -56,7 +56,7 @@ jobs:
             pwntools/pwntools:latest
 
       - name: Build and push ci image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         if: github.event_name == 'workflow_dispatch' || (github.event_name == 'push' && github.ref == 'refs/heads/dev')
         with:
           context: "{{defaultContext}}:travis/docker"