chore: Remove Ruby 2.7 from CI (#19970)

Author: dazuma

.github/workflows/ci.yml

@@ -13,9 +13,6 @@ jobs:
     strategy:
       matrix:
         include:
-          - os: ubuntu-latest
-            ruby: "2.7"
-            task: "--include-spec"
           - os: ubuntu-latest
             ruby: "3.0"
             task: "--include-spec"