Merge pull request #89 from tomykaira/ruby_3.4

CI against for Ruby 3.3 and 3.4

Author: sue445

.github/workflows/rspec.yml

@@ -11,7 +11,14 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ['2.6', '2.7', '3.0', '3.1', '3.2']
+        ruby-version:
+          - '2.6'
+          - '2.7'
+          - '3.0'
+          - '3.1'
+          - '3.2'
+          - '3.3'
+          - '3.4'
 
     steps:
     - uses: actions/checkout@v4