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There's a warning toast shown if the frontend is considered out-of-date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)

src/platform/settings/constants/coreSettings.ts

@@ -1117,5 +1117,12 @@ export const CORE_SETTINGS: SettingParams[] = [
     tooltip: 'Use new Asset API for model browsing',
     defaultValue: isCloud ? true : false,
     experimental: true
+  },
+  {
+    id: 'Comfy.VersionCompatibility.DisableWarnings',
+    name: 'Disable version compatibility warnings',
+    type: 'hidden',
+    defaultValue: false,
+    versionAdded: '1.34.1'
   }
 ]