ci: add Ruby 3.3 and 3.4

Signed-off-by: Shizuo Fujita <[email protected]>

Author: Watson1978

.github/workflows/linux.yml

@@ -13,6 +13,8 @@ jobs:
           - '3.0'
           - '3.1'
           - '3.2'
+          - '3.3'
+          - '3.4'
         os:
           - ubuntu-latest
     name: Ruby ${{ matrix.ruby }} unit testing on ${{ matrix.os }}