fix: guard sm2 cl-assert error tests behind Emacs-30 skip

The three error-case tests in test-org-drill-determine-next-interval-sm2.el asserted their cl-assert preconditions with a bare should-error :type 'cl-assertion-failed. On Emacs 29, ERT installs a signal-hook that keeps should-error from matching the condition, so the tests failed the 29.4 job outright. Under undercover's edebug instrumentation the same assert dropped into a blocking debugger in batch mode, which hung the coverage job until the 6-hour timeout on every push.

The sm5 and simple8 files already wrap their equivalent error tests in a skip-unless guard for this quirk. I copied that helper into sm2 so all three scheduler files handle Emacs 29 the same way.

0 files changed, 0 insertions, 0 deletions