ci: install correct dependencies for PCRE2

Author: mikyll

.github/workflows/build.yml

@@ -59,7 +59,7 @@ jobs:
         do
           sleep 1 
         done
-        until luarocks install lrexlib-pcre
+        until luarocks install lrexlib-pcre2
         do
           sleep 1
         done
@@ -109,7 +109,7 @@ jobs:
     - name: Install dependencies
       run: |
         luarocks install lualogging
-        luarocks install lrexlib-pcre
+        luarocks install lrexlib-pcre2
         luarocks install luaposix
         luarocks install luasocket
         luarocks install busted