ubuntu.yml in textbringer-1.2.0

- old
+ new

@@ -4,10 +4,10 @@
 
 jobs:
   test:
     strategy:
       matrix:
-        ruby: [ head, 3.1, 3.0, 2.7, 2.6 ]
+        ruby: [ head, 3.1, 3.0, 2.7 ]
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
     - uses: actions/checkout@v2
     - uses: ruby/setup-ruby@v1