rake.yml in mergem-0.0.3

- old
+ new

@@ -13,10 +13,10 @@
       matrix:
         os: [ubuntu-20.04, macos-12]
         ruby: ['2.7', '3.0']
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
       - run: bundle update
       - run: bundle exec rake