Update docker/build-push-action digest to 91df6b8 (#966)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.github/workflows/build_and_test.yaml

@@ -63,7 +63,7 @@ jobs:
 
             - name: Build and push Docker image
               if: steps.changed_files.outputs.any_modified == 'true'
-              uses: docker/build-push-action@eafaea8d0f5853934deece2ffa67af59d936562b
+              uses: docker/build-push-action@91df6b874e498451163feb47610c87c4a218c1ee
               with:
                   context: dockerbuild
                   push: true

.github/workflows/dockerbuild.yaml

@@ -35,7 +35,7 @@ jobs:
                       type=ref,event=branch
 
             - name: Build and push Docker image
-              uses: docker/build-push-action@eafaea8d0f5853934deece2ffa67af59d936562b
+              uses: docker/build-push-action@91df6b874e498451163feb47610c87c4a218c1ee
               with:
                   context: dockerbuild
                   push: true