chore(core): typo fix

[Gakunt]

Why are these changes needed?

Found a few typos, one is an error message, rest are comments. This shouldn't require testing or a changelog entry.

Checks

• I've made sure the lint is passing in this PR.
• I've made sure the tests are passing. Note that there might be a few flaky tests, in that case, please comment that they are not relevant.
• Testing Strategy
  • Unit tests
  • Integration tests
  • This PR is not tested :(

[ian-shim]

Thanks for contributing!