🔧 Ruby のバージョンを 2.75 にする

dodonki1223 · dodonki1223 · commit bfbc6b497d4a · 2023-03-25T18:43:47.000+09:00
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu, macos]
-        ruby: [2.6, 2.7]
+        ruby: [2.7]
     runs-on: ${{ matrix.os }}-latest
     steps:
       - uses: actions/checkout@v2
diff --git a/.tool-versions b/.tool-versions
@@ -0,0 +1 @@
+ruby 2.7.5
