Update .github/workflows/ruby.yml

Co-authored-by: Sutou Kouhei <kou@cozmixng.org>

Author: tadeja

.github/workflows/ruby.yml

@@ -168,6 +168,7 @@ jobs:
           echo "PKG_CONFIG_PATH=${PROTOBUF_PREFIX}/lib/pkgconfig:${PKG_CONFIG_PATH}" >> "$GITHUB_ENV"
           echo "CMAKE_PREFIX_PATH=${PROTOBUF_PREFIX}:${ARROW_HOME}:${CMAKE_PREFIX_PATH}" >> "$GITHUB_ENV"
           echo "${PROTOBUF_PREFIX}/bin" >> "$GITHUB_PATH"
+
           # For Meson.
           # See also: https://github.com/mesonbuild/meson/issues/7701
           echo "PKG_CONFIG=$(brew --prefix pkgconf)/bin/pkgconf" >> $GITHUB_ENV