tests: Add skip condition for test_ctrl_c_interrupt under MicroPython.

This test must run with CPython as it spawns a subprocess. Skip it when
run by the test framework which executes tests with MicroPython.

Signed-off-by: Andrew Leech <[email protected]>

Author: pi-anl

tests/ports/unix/test_ctrl_c_interrupt.py

@@ -6,7 +6,13 @@
 and sends SIGINT to verify it generates KeyboardInterrupt.
 """
 
-import pty
+# This test must be run with CPython as it spawns a subprocess
+try:
+    import pty
+except ImportError:
+    print("SKIP")
+    raise SystemExit
+
 import os
 import subprocess
 import select