test: mark SEA tests as flaky on PowerPC

Author: joyeecheung

test/sequential/sequential.status

@@ -46,3 +46,11 @@ test-watch-mode-inspect: PASS, FLAKY
 [$arch==s390x]
 # https://github.com/nodejs/node/issues/41286
 test-performance-eventloopdelay: PASS, FLAKY
+
+[$arch==ppc]
+# https://github.com/nodejs/node/issues/50740
+test-single-executable-application-empty: PASS, FLAKY
+test-single-executable-application-snapshot-and-code-cache: PASS, FLAKY
+test-single-executable-application-snapshot: PASS, FLAKY
+test-single-executable-application-use-code-cache: PASS, FLAKY
+test-single-executable-application: PASS, FLAKY