Install lua dependencies via apt instead of luarocks.

This avoids installing luarocks, which has a few extra deps of its own.

These apt packages contain four copies, for lua 5.1 through 5.4, but that should
be much less expensive than installing luarocks and its deps.

.github/workflows/tests.yml

@@ -16,12 +16,7 @@ jobs:
     - name: Install depenencies
       run: |
         sudo apt-get update
-        sudo apt-get install luajit libluajit-5.1-dev libjavascriptcoregtk-4.0-dev libwebkit2gtk-4.1-dev libgtk-3-dev libglib2.0-dev luarocks
-    - name: Install lua dependencies
-      run: |
-        sudo luarocks --lua-version 5.1 install luafilesystem
-        sudo luarocks --lua-version 5.1 install luassert
-        sudo luarocks --lua-version 5.1 install luacheck
+        sudo apt-get install luajit libluajit-5.1-dev libjavascriptcoregtk-4.0-dev libwebkit2gtk-4.1-dev libgtk-3-dev libglib2.0-dev lua-check lua-luassert lua-filesystem lua-socket
     - name: make
       run: make
     - name: make run-tests