changing from pull requests to pull request

Author: ygicp

.github/workflows/action.yaml

@@ -18,7 +18,7 @@ jobs:
               run : echo "Hello world"
               shell: bash
     goodbye:
-        runs-on: ububntu-latest
+        runs-on: ubuntu-latest
         steps:
             - name: Goodbye
               run: echo "goodbye"