macos-latest -> macos-13

This commit fixes:
```
xcodebuild: error: Failed to build project AeroSpace with scheme AeroSpace.
	Reason: Cannot test target “AeroSpace-Tests” on “My Mac”: My Mac’s macOS 12.6.8 doesn’t match AeroSpace-Tests’s macOS 13.1 deployment target.
Error: Process completed with exit code 70.
```

From https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#choosing-github-hosted-runnersj
    macOS 13 Ventura [Beta]	macos-13 or macos-13-xl	None
    macOS 12 Monterey	macos-latest, macos-12, macos-latest-xl or macos-12-xl	The macos-latest and macos-latest-xl workflow labels currently uses the macOS 12 runner image

.github/workflows/build.yml

@@ -11,7 +11,7 @@ on:
 jobs:
   build:
     name: Build
-    runs-on: macos-latest
+    runs-on: macos-13
 
     steps:
       - name: Checkout