Bump docker/build-push-action from 6 to 7 (eclipse-basyx#1089)

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
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/docker-prerelease-ui.yml

@@ -55,7 +55,7 @@ jobs:
         run: echo "SHORT_SHA=${GITHUB_SHA:0:7}" >> $GITHUB_ENV
 
       - name: Build and Push Docker Image (Pre-release)
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@v7
         with:
           context: ./aas-web-ui
           file: ./aas-web-ui/Dockerfile

.github/workflows/docker-release-ui.yml

@@ -60,7 +60,7 @@ jobs:
 
       # Step 5: Build and Push Docker Images
       - name: Build and Push Docker Images
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@v7
         with:
           context: ./aas-web-ui
           file: ./aas-web-ui/Dockerfile