tests/pexpects/fish_indent_interrupt: skip in CI

This fails intermittently in CI. Disable it.  We disable a lot of
other tests as well which is why we run tests on developer machines
before pushing to master.

See #12351

tests/pexpects/fish_indent_interrupt.py

@@ -1,5 +1,9 @@
 #!/usr/bin/env python3
 from pexpect_helper import SpawnedProc
+import os
+
+if "CI" in os.environ:
+    sys.exit(127)
 
 sp = SpawnedProc(timeout=2)
 send, sendline, sleep, expect_prompt = (