Merge branch 'ci/fix_ut_s2_only' into 'master'

ci: fix the issue unit_test_s2 label cannot be used independently

See merge request espressif/esp-idf!7873

tools/ci/config/assign-test.yml

@@ -27,6 +27,7 @@ assign_test:
     variables:
       - $BOT_TRIGGER_WITH_LABEL == null
       - $BOT_LABEL_UNIT_TEST
+      - $BOT_LABEL_UNIT_TEST_S2
       - $BOT_LABEL_INTEGRATION_TEST
       - $BOT_LABEL_EXAMPLE_TEST
       - $BOT_LABEL_CUSTOM_TEST

tools/ci/config/build.yml

@@ -20,6 +20,7 @@
       - $BOT_TRIGGER_WITH_LABEL == null
       - $BOT_LABEL_BUILD
       - $BOT_LABEL_UNIT_TEST
+      - $BOT_LABEL_UNIT_TEST_S2
       - $BOT_LABEL_REGULAR_TEST
 
 .build_ssc_template: