ci: include coverage of ruby 3.1 and jruby 9.3

Author: flavorjones

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ["2.2", "2.3", "2.4", "2.5", "2.6", "2.7", "3.0", "ruby-head"]
+        ruby: ["2.2", "2.3", "2.4", "2.5", "2.6", "2.7", "3.0", "3.1", "ruby-head"]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
@@ -35,7 +35,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ["jruby-9.2", "jruby-head"]
+        ruby: ["jruby-9.2", "jruby-9.3", "jruby-head"]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2