Auto merge of #23654 - julientregoat:issue-23645, r=jdm

Fix panic when running test-background-fetch-permission.html

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* Propagate `Error::JSFailed` in `Permissions::create_descriptor`
* In `Error::to_jsval`, only check if a JS exception is not pending if `self` is not `Error::JSFailed`

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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #23645 (GitHub issue number if applicable)

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- [x] These changes do not require tests because it's a test runner, so by nature if the test runs the test runner is also working as expected.

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