Update x86_64-darwin.yml

Author: angerman

.github/workflows/x86_64-darwin.yml

@@ -5,7 +5,6 @@ on:
 
 jobs:
   build:
-    if: false  # Disabled until macOS hydra builders are back online
     name: Prebuild and Upload
     uses: ./.github/workflows/main.yml
     with: