Bump docker/build-push-action from 6 to 7

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 6 to 7.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v6...v7)

---
updated-dependencies:
- dependency-name: docker/build-push-action
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/docker.yml

@@ -41,7 +41,7 @@ jobs:
         run: echo "VERSION=$(cat splitio/version.go | grep 'Version =' | awk '{print $4}' | tr -d '"')" >> $GITHUB_ENV
 
       - name: Docker Build and Push
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@v7
         with:
           context: .
           file: "infra/sidecar.Dockerfile"

.github/workflows/unstable.yml

@@ -40,7 +40,7 @@ jobs:
         run: echo "SHORT_SHA=$(git rev-parse --short HEAD)" >> $GITHUB_ENV
 
       - name: Docker Build and Push
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@v7
         with:
           context: .
           file: "infra/sidecar.Dockerfile"