Fix lint errors on commit 5892d7cdc (#25367)

Fixes lint errors and e2e failures on v11.16.12, which would have been
introduced during conflict resolution when cherry-picking #24605

Specifically:
- `test/e2e/default-fixture.js` is deleted as that file does not exist
on master yet and is not used. However, importantly, the change made in
`test/e2e/default-fixture.js` in #24605 is now applied to
`test/e2e/fixture-builder.js` (this was needed for e2e tests to pass)
- delete
`ui/pages/settings/security-tab/metametrics-toggle/metametrics-toggle.tsx`
and the associated test file, as these seem to be unused
- delete unused variables in
`ui/pages/settings/security-tab/security-tab.component.js`

test/e2e/fixture-builder.js

@@ -114,6 +114,7 @@ function defaultFixture(inputChainId = CHAIN_IDS.LOCALHOST) {
         fragments: {},
         metaMetricsId: null,
         participateInMetaMetrics: false,
+        dataCollectionForMarketing: false,
         traits: {},
       },
       NetworkController: {