.github: workflows: clang: install python packages

Always install current python dependencies required for CI as part of
setting up the workflow, since the ones pulled in the docker image may
be out of date.

Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>

Author: kartben

.github/workflows/clang.yaml

@@ -86,6 +86,10 @@ jobs:
           gcc --version
           ls -la
 
+      - name: Install Python packages
+        run: |
+          pip install -r scripts/requirements-actions.txt --require-hashes
+
       - name: Set up ccache
         run: |
           mkdir -p ${CCACHE_DIR}