Remove ruby version references in ci checks

Github Actions defaults to .ruby-version

Also reintroducing the bundler cache, and ignore vendored gems from typecheck
as it was causing typecheck to fail instead of bundle installing manually

.github/workflows/ci.yml

@@ -63,7 +63,6 @@ jobs:
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: "3.1"
           bundler-cache: true
       - name: Run style checks
         run: bin/rubocop
@@ -75,12 +74,9 @@ jobs:
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: "3.1"
-          # bundler-cache: true
+          bundler-cache: true
       - name: Run static type checks
-        run: |
-          bundle install --jobs 4 --retry 3
-          bin/srb tc
+        run: bin/srb tc
   buildall:
     if: ${{ always() }}
     runs-on: ubuntu-latest

sorbet/config

@@ -1,3 +1,4 @@
 --dir
 .
 --enable-experimental-requires-ancestor
+--ignore=/vendor/bundle