chore(deps): Bump docker/build-push-action from 4.1.1 to 4.2.1 (#3533)

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

.github/workflows/generic_build.yml

@@ -83,7 +83,7 @@ jobs:
 
       # NOTE: AMD64 can build within 2 minutes
       - name: 'Build images'
-        uses: docker/build-push-action@v4.1.1
+        uses: docker/build-push-action@v4.2.1
         with:
           context: .
           # Build at least the AMD64 image (which runs against the test suite).

.github/workflows/generic_publish.yml

@@ -72,7 +72,7 @@ jobs:
         run: echo "version=$(<VERSION)" >>"${GITHUB_OUTPUT}"
 
       - name: 'Build and publish images'
-        uses: docker/build-push-action@v4.1.1
+        uses: docker/build-push-action@v4.2.1
         with:
           context: .
           build-args: |

.github/workflows/generic_test.yml

@@ -43,7 +43,7 @@ jobs:
       # Importing from the cache should create the image within approx 30 seconds:
       # NOTE: `qemu` step is not needed as we only test for AMD64.
       - name: 'Build AMD64 image from cache'
-        uses: docker/build-push-action@v4.1.1
+        uses: docker/build-push-action@v4.2.1
         with:
           context: .
           tags: mailserver-testing:ci

.github/workflows/generic_vulnerability-scan.yml

@@ -42,7 +42,7 @@ jobs:
       # Importing from the cache should create the image within approx 30 seconds:
       # NOTE: `qemu` step is not needed as we only test for AMD64.
       - name: 'Build AMD64 image from cache'
-        uses: docker/build-push-action@v4.1.1
+        uses: docker/build-push-action@v4.2.1
         with:
           context: .
           tags: mailserver-testing:ci