Drop support for armv7 Docker builds.

.github/workflows/docker.yml

@@ -92,7 +92,7 @@ jobs:
               with:
                   context: .
                   push: true
-                  platforms: linux/amd64,linux/arm64,linux/arm/v7
+                  platforms: linux/amd64,linux/arm64
                   tags: ${{ steps.meta.outputs.tags }}
                   labels: ${{ steps.meta.outputs.labels }}
                   cache-from: type=local,src=/tmp/.buildx-cache/linux/amd64