ci: CI against Ruby v3.4

rspec -> test

Author: toshimaru

.github/workflows/test.yml

@@ -2,11 +2,11 @@ name: Test
 on:
   push:
 jobs:
-  rspec:
+  test:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest]
-        ruby: ['2.7', '3.0', '3.1', '3.2', '3.3']
+        ruby: ["2.7", "3.0", "3.1", "3.2", "3.3", "3.4"]
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4