making Mbed Unit Tests return an Error to clarify that they are disabled

Author: Alami-Amine

src/test_driver/mbed/unit_tests/main/main.cpp

@@ -62,12 +62,14 @@ int main()
 
     ChipLogProgress(NotSpecified, "Mbed unit-tests application run");
 
-    int status = 0;
     // Migration to pw_unit_tests was not done for mbed since the unit-testing FW used to run out of flash and was disabled from
     // GitHub Actions workflows: https://github.com/project-chip/connectedhomeip/pull/15966
 
-    // status += RunRegisteredUnitTests();
+    // int status = RunRegisteredUnitTests();
     // ChipLogProgress(NotSpecified, "CHIP test status: %d", status);
 
+    ChipLogError(NotSpecified, "Unit Tests are currently DISABLED for Mbed");
+    int status = 1;
+
     return status;
 }