chore(docker): update build-push-action to v6.15.0

Author: noirbee

ALLOWED_ACTIONS.yaml

@@ -12,7 +12,7 @@ cirrus-actions/rebase: c473b716e3fcde0c6bf67416e2c2882830ad40f6  # 1.5
 codecov/codecov-action: f32b3a3741e1053eb607407145bc9619351dc93b  # v2.1.0
 cypress-io/github-action: 6b3bc3a1c27198cda160cb03307c43bc998aa564  # v2.11.0
 de-vri-es/setup-git-credentials: 162b9dfe472513ee2960f0c97dd3cbbe80319b68  # v2.0.10
-docker/build-push-action: c56af957549030174b10d6867f20e78cfd7debc5 # v3.2.0
+docker/build-push-action: 471d1dc4e07e5cdedd4c2171150001c434f0b7a4  # v6.15.0
 docker/login-action: f4ef78c080cd8ba55a85445d5b36e214a81df20a  # v2.1.0
 docker/metadata-action: f206c36955d3cc6213c38fb3747d9ba4113e686a  # v4.0.0
 docker/setup-buildx-action: 8c0edbc76e98fa90f69d9a2c020dcb50019dc325  # v2.2.1