fix: restoring localhost to list of known hosts

[krpeacock]

Description

It's unclear where this regression began, but obviously localhost should have been in the list instead of a duplicated 127.0.0.1. Resolves the mysterious subnet_not_found error from local development while using localhost domain

Checklist:

• My changes follow the guidelines in CONTRIBUTING.md.
• The title of this PR complies with Conventional Commits.
• I have edited the CHANGELOG accordingly.
• I have made corresponding changes to the documentation.

[github-actions]

size-limit report 📦

Path	Size
@dfinity/agent	98.58 KB (+0.01% 🔺)
@dfinity/candid	13.41 KB (0%)
@dfinity/principal	5.01 KB (0%)
@dfinity/auth-client	90.58 KB (0%)
@dfinity/assets	91.11 KB (0%)
@dfinity/identity	88.06 KB (0%)
@dfinity/identity-secp256k1	254.38 KB (+0.01% 🔺)