fix(provider): fix metamask provider (#39)

Description
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Importing `tari.js` with the Metamask package `"@metamask/providers":
"^9.0.0"` caused TypeScript error in a not directly related piece of
code. To fix it bump package version and define `type Maybe<T> = T |
null | undefined;` in `MetamaskTariProvider` class.

Motivation and Context
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Error getting while launching Tari Universe app.

![image](https://github.com/user-attachments/assets/663428b9-ff8f-4455-bd12-715ddc1efcba)


How Has This Been Tested?
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Manually with local build.

What process can a PR reviewer use to test or verify this change?
---

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Breaking Changes
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- [x] None
- [ ] Requires data directory on base node to be deleted
- [ ] Requires hard fork
- [ ] Other - Please specify

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