build(deps): bump docker/build-push-action from 2 to 6 (#8465)

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 2 to 6.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](https://github.com/docker/build-push-action/compare/v2...v6)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Zamil Majdy <zamil.majdy@agpt.co>

.github/workflows/classic-autogpt-docker-cache-clean.yml

@@ -23,7 +23,7 @@ jobs:
 
       - id: build
         name: Build image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: classic/
           file: classic/Dockerfile.autogpt

.github/workflows/classic-autogpt-docker-ci.yml

@@ -47,7 +47,7 @@ jobs:
 
       - id: build
         name: Build image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: classic/
           file: classic/Dockerfile.autogpt
@@ -117,7 +117,7 @@ jobs:
 
       - id: build
         name: Build image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: classic/
           file: classic/Dockerfile.autogpt

.github/workflows/classic-autogpt-docker-release.yml

@@ -42,7 +42,7 @@ jobs:
 
       - id: build
         name: Build image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: classic/
           file: Dockerfile.autogpt