Temporarily disable failing case in CI:

- lib.libexecinfo.backtrace_test.backtrace_fmt_basic

PR:		241562
Sponsored by:	The FreeBSD Foundation

contrib/netbsd-tests/lib/libexecinfo/t_backtrace.c

@@ -151,6 +151,9 @@ ATF_TC_HEAD(backtrace_fmt_basic, tc)
 
 ATF_TC_BODY(backtrace_fmt_basic, tc)
 {
+	if (atf_tc_get_config_var_as_bool_wd(tc, "ci", false))
+		atf_tc_skip("https://bugs.freebsd.org/241562");
+
 	myfunc(12);
 
 	if (prevent_inline)