Remove macos-10.05 image (#121)

`macos-10.05` will be removed by 2023-03-31.

Author: hsbt

.github/workflows/ci.yml

@@ -13,8 +13,8 @@ jobs:
       fail-fast: false
       matrix:
         os:
-          - macos-10.15
-          - macos-11.0
+          - macos-11
+          - macos-12
           - ubuntu-latest
           - windows-latest
         ruby: