And bump the github actions too

Author: peterix

.github/workflows/release.yml

@@ -24,7 +24,7 @@ jobs:
             - name: Install zig
               uses: mlugg/setup-zig@v2
               with:
-                  version: 0.14.0
+                  version: 0.15.1
 
             - name: Build
               env:

.github/workflows/test.yml

@@ -9,5 +9,5 @@ jobs:
       - uses: actions/checkout@v3
       - uses: mlugg/setup-zig@v2
         with:
-          version: 0.14.0
+          version: 0.15.1
       - run: make test