Bump @primer/primitives to 7.11.5 (#3120)

* npm install @primer/[email protected]

* Updating`theme-preval` snapshots

* Re-run

```
npm run build
npm run test -- -u
```

So that /themePreval.test.ts.snap also gets the new timestamp

* Update `theme-preval` snapshots docs

* Create .changeset/old-falcons-learn.md

* test(vrt): update snapshots

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Co-authored-by: simurai <[email protected]>

Author: simurai