fix luarocks to v5

Author: chensunny

.github/workflows/test.yml

@@ -10,7 +10,7 @@ jobs:
     - uses: leafo/gh-actions-lua@v8
       with:
         luaVersion: "luajit-openresty"
-    - uses: leafo/gh-actions-luarocks@v4
+    - uses: leafo/gh-actions-luarocks@v5
     - run: luarocks install luacheck
     - run: luacheck lib