CI: Set Ruby version in Sorbet job

Author: 64kramsystem

.github/workflows/ci.yml

@@ -2,12 +2,15 @@ name: CI
 
 on: [pull_request]
 
+env:
+  SORBET_RUBY: 3.4
+
 jobs:
   test:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: [head, 3.4, 3.3, 3.2]
+        ruby-version: [head, ${{ env.SORBET_RUBY }}, 3.3, 3.2]
       fail-fast: false
     continue-on-error: ${{ endsWith(matrix.ruby, 'head') || matrix.ruby == 'debug' }}
     steps:
@@ -26,6 +29,7 @@ jobs:
           fetch-depth: ${{ env.REPO_FETCH_DEPTH }}
       - uses: ruby/setup-ruby@v1
         with:
+          ruby-version: ${{ env.SORBET_RUBY }}
           bundler-cache: true
       - name: Sorbet
         run: bundle exec srb typecheck