Add Ruby 3.0 and 3.1 to the CI matrix

Author: petergoldstein

.github/workflows/sqlite3-ruby.yml

@@ -12,7 +12,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu, macos ]
-        ruby: [ head, 2.7, 2.6, 2.5, 2.4, 2.3, 2.2, truffleruby-head ]
+        ruby: [ head, 3.1, '3.0', 2.7, 2.6, 2.5, 2.4, 2.3, 2.2, truffleruby-head ]
     steps:
       - uses: actions/checkout@v2
       - name: load Ruby and dependencies
@@ -37,7 +37,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [windows ]
-        ruby: [ mingw, 2.7, 2.6, 2.5, 2.4 ]
+        ruby: [ mingw, 3.1, '3.0', 2.7, 2.6, 2.5, 2.4 ]
     steps:
       - uses: actions/checkout@v2
       - name: load Ruby and sqlite3