fix gha

Author: rarruda

.github/workflows/pull_request.yml

@@ -20,7 +20,7 @@ jobs:
       run: bundle exec rubocop
     - name: Run Steep / RBS Type signature verification
       run: |
-        steep check --steepfile=./Steepfile --severity-level=error | ruby -pe 'sub(/^(.+):(\d+):(\d+): (.+)$/, %q{::error file=\1,line=\2,col=\3::\4})'
+        bundle exec steep check --steepfile=./Steepfile --severity-level=error | ruby -pe 'sub(/^(.+):(\d+):(\d+): (.+)$/, %q{::error file=\1,line=\2,col=\3::\4})'
       shell: bash
 
   test: