Bump docker/build-push-action from 3 to 6

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 3 to 6.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v3...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>

.github/workflows/merge.yml

@@ -66,7 +66,7 @@ jobs:
           echo "EGERIA_VERSION=$(./gradlew dependencies | grep org.odpi.egeria:open-connector-framework | awk -F':' '{if ($3) print $3}' | awk -F' ' '{print $1}' | uniq| head -1)" >> $GITHUB_ENV
       - name: Build and push to quay.io and docker.io (tag latest only for main!)
         if: ${{ github.ref == 'refs/heads/main'}}
-        uses: docker/build-push-action@v3
+        uses: docker/build-push-action@v6
         with:
           context: .
           push: true
@@ -78,7 +78,7 @@ jobs:
             EGERIA_VERSION=${{ env.EGERIA_VERSION }}
       - name: Build and push( to quay.io and docker.io (no tag latest)
         if: ${{ github.ref != 'refs/heads/main'}}
-        uses: docker/build-push-action@v3
+        uses: docker/build-push-action@v6
         with:
           context: .
           push: true

.github/workflows/release.yml

@@ -59,7 +59,7 @@ jobs:
           echo "EGERIA_BASE_IMAGE=quay.io/odpi/egeria" >> $GITHUB_ENV
           echo "EGERIA_VERSION=$(./gradlew dependencies | grep org.odpi.egeria:open-connector-framework | awk -F':' '{if ($3) print $3}' | awk -F' ' '{print $1}' | uniq| head -1)" >> $GITHUB_ENV
       - name: Build and push( to quay.io and docker.io (no tag latest)
-        uses: docker/build-push-action@v3
+        uses: docker/build-push-action@v6
         with:
           context: .
           push: true