ci: Run all Blackbox tests

We've previously restricted Blackbox test
runs to just one test file - test_output.py.
That was a mistake.

This commit makes the relevant workflow run
all of the blackbox test files again.

Signed-off-by: Lukasz Mrugala <[email protected]>

Author: LukaszMrugala

.github/workflows/twister_tests_blackbox.yml

@@ -62,4 +62,4 @@ jobs:
         export ZEPHYR_SDK_INSTALL_DIR=${{ github.workspace }}/zephyr-sdk
         echo "Run twister tests"
         source zephyr-env.sh
-        PYTHONPATH="./scripts/tests" pytest ./scripts/tests/twister_blackbox/test_output.py
+        PYTHONPATH="./scripts/tests" pytest ./scripts/tests/twister_blackbox/