Bump tar and web3 in /tkey-mpc-web/tkey-mpc-react-bitcoin-example

Removes [tar](https://github.com/isaacs/node-tar). It's no longer used after updating ancestor dependency [web3](https://github.com/ChainSafe/web3.js). These dependencies need to be updated together.


Removes `tar`

Updates `web3` from 1.10.2 to 4.7.0
- [Release notes](https://github.com/ChainSafe/web3.js/releases)
- [Changelog](https://github.com/web3/web3.js/blob/4.x/CHANGELOG.md)
- [Commits](web3/web3.js@v1.10.2...v4.7.0)

---
updated-dependencies:
- dependency-name: tar
  dependency-type: indirect
- dependency-name: web3
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>