build(deps): bump docker/build-push-action from 4 to 7

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 4 to 7.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v4...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/release.yml

@@ -12,7 +12,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v6
       - name: Build docs
-        uses: docker/build-push-action@v4
+        uses: docker/build-push-action@v7
         with:
           context: .
           target: docs-site
@@ -31,7 +31,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v6
       - name: Run tests
-        uses: docker/build-push-action@v4
+        uses: docker/build-push-action@v7
         with:
           context: .
           target: test

.github/workflows/test.yml

@@ -15,12 +15,12 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v6
       - name: Run tests
-        uses: docker/build-push-action@v4
+        uses: docker/build-push-action@v7
         with:
           context: .
           target: test
       - name: Test doc build
-        uses: docker/build-push-action@v4
+        uses: docker/build-push-action@v7
         with:
           context: .
           target: docs-site