Update release job on macOS to macos-15 runner

Summary: After D89732829 has gotten a successful build, might as well try the next version.

Reviewed By: bigfootjon

Differential Revision: D89732830

fbshipit-source-id: cf66bd2873020749156da5cd8522a04ce171c1e1

Author: David Tolnay

.github/workflows/release.yml

@@ -21,7 +21,7 @@ jobs:
 
   macos:
     needs: create-release
-    runs-on: macos-14
+    runs-on: macos-15
     timeout-minutes: 30
     steps:
       - uses: actions/checkout@v6