ci: clang: Remove obsolete clean-up steps

The repository clean-up steps are no longer necessary because the new
zephyr-runner is ephemeral and does not contain any files from the
previous runs.

Signed-off-by: Stephanos Ioannidis <[email protected]>

Author: stephanosio

.github/workflows/clang.yaml

@@ -26,11 +26,6 @@ jobs:
     outputs:
       report_needed: ${{ steps.twister.outputs.report_needed }}
     steps:
-      - name: Cleanup
-        run: |
-          # hotfix, until we have a better way to deal with existing data
-          rm -rf zephyr zephyr-testing
-
       - name: Clone cached Zephyr repository
         continue-on-error: true
         run: |