Skip a broken test on (and ecl os-macosx)

See: https://gitlab.com/embeddable-common-lisp/ecl/-/issues/600
11 jobs for macos-runner in 23 minutes and 33 seconds (queued for 2 seconds)
latest
Status Name Job ID Coverage
  Build
passed Build ASDF #6870

00:02:40

passed Build docs #6871

00:05:00

 
  Regression
canceled ABCL 1.7.1 regression tests #6873

passed ABCL MacOS regression tests #6877
macos

00:12:09

passed ABCL regression tests #6872

00:23:32

passed CCL MacOS regression tests #6878
macos

00:02:16

passed CCL regression tests #6874

00:06:42

passed ECL MacOS regression tests #6879
macos

00:04:33

passed ECL regression tests #6875

00:06:39

passed SBCL MacOS regression tests #6880
macos

00:02:05

passed SBCL regression tests #6876

00:04:43