Master branch should use zig version master for coverage

Author: KurtWagner

.github/workflows/coverage.yml

@@ -20,7 +20,7 @@ jobs:
       - name: "Setup zig environment"
         uses: mlugg/setup-zig@v2
         with:
-          version: 0.14.1
+          version: master
 
       - run: zig env