test: mark test-child-process-execfile flaky

Refs: nodejs#25029

PR-URL: nodejs#25051
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>

Author: Trott

test/parallel/parallel.status

@@ -5,6 +5,8 @@ prefix parallel
 # sample-test                        : PASS,FLAKY
 
 [true] # This section applies to all platforms
+# https://github.com/nodejs/node/issues/25029
+test-child-process-execfile: PASS,FLAKY
 # https://github.com/nodejs/node/issues/23207
 test-net-connect-options-port: PASS,FLAKY
 # https://github.com/nodejs/node/issues/25033