[test] fix reporting expect failure (#6869)

This commit fixes reporting expect failures by adding fail on error
flag to the ot_exec_expect_script function in script/test script.

This commit also fixes failing expect tests and removes expect tests
on macOS for unstable issues.

tests/scripts/expect/cli-counters.exp

@@ -32,9 +32,9 @@ source "tests/scripts/expect/_common.exp"
 spawn_node 1
 
 send "counters\n"
+expect "ip"
 expect "mac"
 expect "mle"
-expect "ip"
 expect_line "Done"
 send "counters mac\n"
 expect_line "Done"