Update test.yml (#41)

Author: juno-nishizaki

.github/workflows/test.yml

@@ -11,7 +11,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [2.4, 2.5, 2.6, 2.7]
+        ruby: [2.5, 2.6, 2.7]
         db_version: [5.7]
     runs-on: ubuntu-latest
     container:
@@ -41,7 +41,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [2.4, 2.5, 2.6, 2.7]
+        ruby: [2.5, 2.6, 2.7]
         db_version: [9.5]
     runs-on: ubuntu-latest
     container:
@@ -75,7 +75,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [2.4, 2.5, 2.6, 2.7]
+        ruby: [2.5, 2.6, 2.7]
     runs-on: ubuntu-latest
     container:
       image: ruby:${{ matrix.ruby }}