Print config.log on config failure

Author: NattyNarwhal

.github/actions/configure-gentoo/action.yml

@@ -77,3 +77,7 @@ runs:
           ${{ inputs.skipSlow == 'false' && '--with-pdo-dblib' || '' }} \
           --enable-werror \
           ${{ inputs.configurationParameters }}
+          || (echo "::group::config.log"
+          cat config.log
+          echo "::endgroup::"
+          exit 1)