fix(staking): fix middleware matcher regex

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Name	Status	Preview	Comments	Updated (UTC)
api-reference	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Sep 24, 2024 5:57am
staking	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Sep 24, 2024 5:57am

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| Name | Status | Preview | Comments | Updated (UTC) | | :--- | :----- | :------ | :------- | :------ | | **xc-admin-frontend** | ⬜️ Ignored ([Inspect](https://vercel.com/pyth-web/xc-admin-frontend/5MvKJeDcCpcdCqByuEASSy3QfcYt)) | [Visit Preview](https://xc-admin-frontend-git-fork-cprussin-fix-middlew-472eab-pyth-web.vercel.app) | | Sep 24, 2024 5:57am |