Install pkgconf

Author: otegami

.github/workflows/test.yml

@@ -53,7 +53,7 @@ jobs:
         if: |
           runner.os == 'Windows'
         run: |
-          ridk exec pacman --sync --noconfirm mingw-w64-x86_64-cairo mingw-w64-ucrt-x86_64-cairo
+          ridk exec pacman --sync --noconfirm mingw-w64-x86_64-cairo mingw-w64-ucrt-x86_64-cairo mingw-w64-x86_64-pkgconf mingw-w64-ucrt-x86_64-pkgconf
       - name: Install dependencies
         run: |
           bundle install