test: temporarily disable flaky test (#1103)

Author: reubeno

brush-shell/tests/cases/compat/builtins/trap.yaml

@@ -364,6 +364,7 @@ cases:
   # differences. Older bash resets traps in coproc, newer bash (5.3.9) inherits them.
   # This causes inconsistent test results across CI runners.
   - name: "coproc - EXIT trap behavior"
+    skip: true # TODO: this test is too inconsistent
     min_oracle_version: "5.3.0"
     incompatible_os:
       - fedora