Replace deprecated ruby action with active one

Author: AdityaHirapara

.github/workflows/gem-push.yml

@@ -13,7 +13,7 @@ jobs:
     steps:
     - uses: actions/checkout@v3
     - name: Set up Ruby 2.6
-      uses: actions/setup-ruby@v1
+      uses: ruby/setup-ruby@v1
       with:
         ruby-version: 2.6.x