test: add setting to ignore version compatibility toast warnings in e2e tests (#7004)

There's a warning toast shown if the frontend is considered out-of-date
(relative to the version in the requirements.txt of
comfyanonymous/ComfyUI). As a result, e2e tests run on older release
branches (e.g., when backporting or hotfixing) can sometimes trigger the
warning which obviously causes visual regression tests to fail. This PR
adds a hidden setting to disable the warning and sets it to `true` in
the e2e test fixtures.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7004-test-add-setting-to-ignore-version-compatibility-toast-warnings-in-e2e-tests-2b86d73d3650812d9e07f54a0c86b996)
by [Unito](https://www.unito.io)

browser_tests/fixtures/ComfyPage.ts

@@ -1651,7 +1651,10 @@ export const comfyPageFixture = base.extend<{
         // Set tutorial completed to true to avoid loading the tutorial workflow.
         'Comfy.TutorialCompleted': true,
         'Comfy.SnapToGrid.GridSize': testComfySnapToGridGridSize,
-        'Comfy.VueNodes.AutoScaleLayout': false
+        'Comfy.VueNodes.AutoScaleLayout': false,
+        // Disable toast warning about version compatibility, as they may or
+        // may not appear - depending on upstream ComfyUI dependencies
+        'Comfy.VersionCompatibility.DisableWarnings': true
       })
     } catch (e) {
       console.error(e)