ci: update zig action and version

Author: fjebaker

.github/workflows/test.yml

@@ -17,9 +17,9 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
       - name: Setup zig
-        uses: mlugg/setup-zig@v1
+        uses: mlugg/setup-zig@v2
         with:
-          version: master
+          version: 0.15.2
       - name: Build and test
         run: zig build test