ci: Fix macOS (#16)

Author: krlmlr

.github/workflows/install/action.yml

@@ -75,6 +75,12 @@ runs:
         echo "_R_CHECK_CRAN_INCOMING_USE_ASPELL_=true" | tee -a $GITHUB_ENV
       shell: bash
 
+    - name: Remove pkg-config@0.29.2
+      if: runner.os == 'macOS'
+      run: |
+        brew uninstall pkg-config@0.29.2
+      shell: bash
+
     - uses: r-lib/actions/setup-pandoc@v2
 
     - uses: r-lib/actions/setup-r@v2