Try "0.15.1" rather than "latest"

Author: jayschwa

.github/workflows/ci.yaml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        zig-version: [0.14.0, 'latest']
+        zig-version: [0.14.0, 0.15.1]
         os: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.os }}
     steps: