.github/workflows/ci.yml: exercise 'zig build test'.

Author: dot-asm

.github/workflows/ci.yml

@@ -268,3 +268,12 @@ jobs:
                 dotnet run -c Release
             fi
         fi
+
+    - name: Zig
+      run: |
+        base_dir=zig-x86_64-linux-0.15.2
+        wget https://ziglang.org/download/0.15.2/$base_dir.tar.xz
+        unxz -c $base_dir.tar.xz | tar xf -
+        if [ -x $base_dir/zig ]; then
+            $base_dir/zig build test
+        fi