docs: update broken link

[Maximilian199603]

What type of PR is this?

Documentation

What does this PR do? Why is it needed?

This PR updates a broken link in validator/keymanager/remote-web3signer/README.md. The previous link to https://docs.prylabs.network/docs/wallet/web3signer was no longer valid. It has been replaced with the correct and updated documentation link: https://www.offchainlabs.com/prysm/docs/manage-wallet/web3signer.

This change is needed to ensure the documentation remains accurate and users can find the correct information regarding web3signer details.

Which issues(s) does this PR fix?

Fixes # (This is a minor documentation fix and does not have an associated issue.)

Other notes for review

before

after

Acknowledgements

• I have read CONTRIBUTING.md.
• I have included a uniquely named changelog fragment file. (For documentation updates, this might not be strictly necessary, but please check the project's specific guidelines.)
• I have added a description to this PR with sufficient context for reviewers to understand this PR.

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