ci: Bump macos runner images (#417)

Closes #416.

Workflows using x86_64-apple-darwin target with a `macos-13` runner
image have been migrated to `macos-15-intel` due to deprecation (see
#416), and `macos-14` images have been migrated to `macos-15`.

.github/workflows/release.yml

@@ -69,7 +69,7 @@ jobs:
   create-release:
     if: startsWith(github.ref_name, 'v')
     needs: [check-version-changed, build]
-    runs-on: macos-14
+    runs-on: macos-15
     environment: tags
     steps:
       - name: Download Artifacts
@@ -126,7 +126,7 @@ jobs:
 
   npm-release:
     needs: [create-release]
-    runs-on: macos-14
+    runs-on: macos-15
     environment: tags
     steps:
       - uses: actions/checkout@v4