[Github][MLGO] Fix mlgo-utils path in new-prs-labeler

This patch (hopefully) fixes the mlgo-utils path in new-prs-labeler so
that it actually matches all files in that directory. Currently it is
not catching the files as they are relatively deeply nested within the
folder.

Author: boomanaiden154

.github/new-prs-labeler.yml

@@ -668,7 +668,7 @@ mlgo:
   - llvm/lib/CodeGen/ML*
   - llvm/unittests/CodeGen/ML*
   - llvm/test/CodeGen/MLRegAlloc/**
-  - llvm/utils/mlgo-utils/*
+  - llvm/utils/mlgo-utils/**
 
 tools:llvm-exegesis:
   - llvm/tools/llvm-exegesis/**