lib.libc.gen.getmntinfo_test.getmntinfo_test is unstable since 8/20, skip it

in CI env temporarily for more offline diagnosis

PR:		240049
Sponsored by:	The FreeBSD Foundation

lib/libc/tests/gen/getmntinfo_test.c

@@ -57,6 +57,9 @@ ATF_TC_BODY(getmntinfo_test, tc)
 	int nmnts;
 	struct statfs *mntinfo;
 
+	if (atf_tc_get_config_var_as_bool_wd(tc, "ci", false))
+		atf_tc_skip("https://bugs.freebsd.org/240049");
+
 	/* Test bogus mode */
 	nmnts = getmntinfo(&mntinfo, 199);
 	ATF_REQUIRE_MSG(nmnts == 0 && errno == EINVAL,