refactor: Fetch rails tags inside the loop

Author: toshimaru

.github/workflows/ci.yml

@@ -61,7 +61,11 @@ jobs:
         with:
           submodules: true
       - name: fetch Rails tags
-        run: cd rails && git fetch --depth=1 origin refs/tags/v7*:refs/tags/v7* refs/tags/v6*:refs/tags/v6* refs/tags/v5*:refs/tags/v5*
+        working-directory: rails
+        run: |
+          for version in v7 v6 v5.2; do
+            git fetch --depth=1 origin refs/tags/${version}*:refs/tags/${version}*
+          done
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: 2.7