Bug 1669000 - [devtools] Add fail-if=fission for browser_dbg_WorkerTargetActor.attach.js r=smaug,ochameau

This test perma fails on Fission since session-history-in-parent was enabled.
The test asserts workers retrieved from BrowsingContext targets as follows:
- go to page1, check we can get worker1
- go to page2, check we can get worker2
- go back to page1, check we can get worker1

On the last step, after navigating back, we are unable to retrieve the worker1 on page1

Differential Revision: https://phabricator.services.mozilla.com/D93251

devtools/client/shared/test/browser.ini

@@ -254,6 +254,7 @@ skip-if = debug # bug 1334683
 [browser_dbg_worker-console-04.js]
 skip-if = e10s && debug
 [browser_dbg_WorkerTargetActor.attach.js]
+fail-if = fission # Fails with Fission + session-history-in-parent (Bug 1669000)
 skip-if = e10s && debug
 [browser_dbg_worker-window.js]
 skip-if = (e10s && debug) || true # Bug 1486974