pytest: fix test on MacOS -- still BROKEN message from l1 during teardown

[MSimeZ]

Important

26.04 FREEZE March 11th: Non-bugfix PRs not ready by this date will wait for 26.06.

RC1 is scheduled on March 23rd

The final release is scheduled for April 15th.

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• The changelog has been updated in the relevant commit(s) according to the guidelines.
• Tests have been added or modified to reflect the changes.
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• Important All PRs must consider how to reverse any persistent changes for tools/lightning-downgrade

fix pyrest FAILED issue mentioned in #9013

[cdecker]

This has since been addressed in #9148. The test itself may still be useful, as a guard against regressions. If you'd like to keep it, please rebase and ping me to reopen.