Use $RUNNER_TEMP for good measure

`runner.temp` is not user-controlled but we replace it with `$RUNNER_TEMP` in any case.

Author: angelapwen

.github/actions/check-codescanning-config/action.yml

@@ -62,13 +62,11 @@ runs:
     - name: Check config
       working-directory: ${{ github.action_path }}
       shell: bash
-      run: ts-node ./index.ts "${{ runner.temp }}/user-config.yaml" '$EXPECTED_CONFIG_FILE_CONTENTS'
+      run: ts-node ./index.ts "$RUNNER_TEMP/user-config.yaml" '$EXPECTED_CONFIG_FILE_CONTENTS'
 
     - name: Clean up
       shell: bash
       if: always()
       run: |
-        rm -rf ${{ runner.temp }}/codescanning-config-cli-test
-        rm -rf ${{ runner.temp }}/user-config.yaml
         rm -rf $RUNNER_TEMP/codescanning-config-cli-test
         rm -rf $RUNNER_TEMP/user-config.yaml