tiny-test-fw: show descriptive error when test case assignment fails:
tiny-test-fw: show descriptive error when test case assignment fails:

Will give hint when any job failed to assign:

```
Please add the following jobs to .gitlab-ci.yml with specific tags:
* Add job with: psram, ESP32_IDF, UT_T1_1
* Add job with: psram, ESP32_IDF, UT_T1_1
```

espressif/esp-idf,armada-ai/esp-idf,armada-ai/esp-idf,armada-ai/esp-idf,mashaoze/esp-idf,mashaoze/esp-idf,mashaoze/esp-idf,mashaoze/esp-idf,armada-ai/esp-idf,www220/esp-idf,mashaoze/esp-idf,espressif/esp-idf,www220/esp-idf,www220/esp-idf,www220/esp-idf,espressif/esp-idf,espressif/esp-idf,www220/esp-idf