ci: lock all kas repos

This guarantees that the build job can be easily replicated later.
The kas will generate a file named base.lock.yml which will later be used instead of base.yml,
we will save the lock file in the persistent storage.

Reference:
https://kas.readthedocs.io/en/latest/userguide/project-configuration.html#working-with-lockfiles

Signed-off-by: Jose Quaresma <[email protected]>

.github/workflows/build-yocto.yml

@@ -29,4 +29,6 @@ jobs:
           export SSTATE_DIR=${PERSISTENT_DIR}/sstate-cache
           mkdir -p $DL_DIR
           mkdir -p $SSTATE_DIR
+          kas dump --update --lock --inplace ci/base.yml
           kas build ci/${{ matrix.machine }}.yml
+          mv ci/base.lock.yml ${PERSISTENT_DIR}