[v4] [core] fix(EditableText): do not use disabled text colors

[adidahiya]

Fixes #4974

Checklist

• Includes tests
• Update documentation

Changes proposed in this pull request:

I believe these color overrides were added in error; we don't want to render text with "disabled" appearance when disabled={true}; rather, that prop controls whether the interactive functionality is enabled on this component.

Reviewers should focus on:

Was there some other intention behind this code?

Screenshot

[blueprint-bot]

[v4] [core] fix(EditableText): do not use disabled text colors when disabled={true}

Previews: documentation | landing | table | modern colors demo

[aycai]

The original change and intent was the placeholder text using the disabled text color and failing contrast. The placeholder color should be the only state that changes (which looks correct on the docs site), so if this is touching the disabled state then removing this is correct.