Remove unnecessary upstream file

Author: kzu

.github/workflows/dotnet-file-core.yml

@@ -117,9 +117,7 @@
 	weak
 [file ".github/workflows/dotnet-file-core.yml"]
 	url = https://github.com/devlooped/oss/blob/main/.github/workflows/dotnet-file-core.yml
-	sha = af171b7a87382ee665ba6fbaeb5f38a3551e1c23
-	etag = 5ce370f52933ab2a4cd50f2b410e842fc5eab23088db2bf98b6c4d4ccdc9022b
-	weak
+	skip
 [file ".github/actions/dotnet/action.yml"]
 	url = https://github.com/devlooped/oss/blob/main/.github/actions/dotnet/action.yml
 	sha = f2b690ce307acb76c5b8d7faec1a5b971a93653e