fix: Update schema builder add/set actions to have unique errors

[guilhermecastros]

Reasons for making this change

I believe adding the same error to the list does not provide additional value.

• Updated schema builder errors list to only contain unique errors
  • addErrors & setErrors were updated

Example

Before

After

Checklist

• I'm updating documentation
  • I've checked the rendering of the Markdown text I've added
• I'm adding or updating code
  • I've added and/or updated tests. I've run npx nx run-many --target=build --exclude=@rjsf/docs && npm run test:update to update snapshots, if needed.
  • I've updated docs if needed
  • I've updated the changelog with a description of the PR
• I'm adding a new feature
  • I've updated the playground with an example use of the feature

[heath-freenome]

@guilhermecastros Thanks for the fix, can you update the CHANGELOG.md as well?

[guilhermecastros]

@heath-freenome Just added to the CHANGELOG.md :)