chore: address some review comments

Author: jskeet

.github/workflows/librarian_config_check.yml

@@ -26,15 +26,15 @@ jobs:
       - name: Config check
         if: steps.filter.outputs.librarian == 'true'
         run: |
-          V="$(sed -n 's/^version: *//p' librarian.yaml)"
+          V=$(go run github.com/googleapis/librarian/cmd/librarian@latest config get version)
           go run "github.com/googleapis/librarian/tool/cmd/configcheck@${V}" .
       - name: Update library versions and regenerate
-        if: failure()
+        if: steps.config-check.outcome == 'failure'
         run: |
           echo "Library configuration is different between state.yaml and librarian.yaml.
           Update library configuration in the configs according to the error message and
           regenerate libraries using:
           
-          V=\$(sed -n 's/^version: *//p' librarian.yaml)
+          V=$(go run github.com/googleapis/librarian/cmd/librarian@latest config get version)
           go run github.com/googleapis/librarian/cmd/librarian@\${V} generate --all
           "