Replace environment self-assembly with pre-build Zig image

.drone.yml

@@ -3,14 +3,6 @@ name: Build and Test
 
 steps:
 - name: Build and Test
-  image: alpine
+  image: euantorano/zig:0.9.1
   commands:
-  - apk update && apk add curl xz
-  - mkdir -p /deps
-  - cd /deps
-  - curl https://ziglang.org/deps/zig+llvm+lld+clang-$(uname -m)-linux-musl-0.9.1.tar.xz -O
-  - tar xf zig+llvm+lld+clang-$(uname -m)-linux-musl-0.9.1.tar.xz
-  - mv zig+llvm+lld+clang-$(uname -m)-linux-musl-0.9.1/ local/
-  - cd /drone/src/
-  - apk --no-cache add libc-dev
   - zig test src/main.zig