Don't test libmysqlclient with mysqli on mysql 8.4

There are compile errors with 8.4 that we are no longer fixing.

Author: iluuu1994

.github/workflows/nightly.yml

@@ -814,15 +814,17 @@ jobs:
         with:
           withMysqli: ${{ inputs.libmysqlclient_with_mysqli }}
       - name: Build mysql-8.4
-        uses: ./.github/actions/build-libmysqlclient
+        if: ${{ !inputs.libmysqlclient_with_mysqli }}
+        uses: ./.github/actions/build-libmysqlclient'
         with:
-          configurationParameters: ${{ !inputs.libmysqlclient_with_mysqli && '--enable-werror' || '' }}
+          configurationParameters: --enable-werror
           libmysql: mysql-8.4.0-linux-glibc2.28-x86_64.tar.xz
-          withMysqli: ${{ inputs.libmysqlclient_with_mysqli }}
+          withMysqli: false
       - name: Test mysql-8.4
+        if: ${{ !inputs.libmysqlclient_with_mysqli }}
         uses: ./.github/actions/test-libmysqlclient
         with:
-          withMysqli: ${{ inputs.libmysqlclient_with_mysqli }}
+          withMysqli: false
       - name: Verify generated files are up to date
         uses: ./.github/actions/verify-generated-files
       - name: Notify Slack