Chore: update the migration banner

[katspaugh]

What it solves

Update the migration banner with a deprecation date.

[github-actions[bot]]

CLA Assistant Lite All Contributors have signed the CLA.

[github-actions[bot]]

ESLint Summary View Full Report

Annotations are provided inline on the Files Changed tab. You can also see all annotations that were generated on the annotations page.

Type	Occurrences	Fixable
Errors	0	0
Warnings	0	0
Ignored	0	N/A

• Result: :white_check_mark: success
  • Annotations: 0 total

---

^{Report generated by eslint-plus-action}

[coveralls]

Pull Request Test Coverage Report for Build 3873886755

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 41.875%

---

Totals
Change from base Build 3741558067:	0.0%
Covered Lines:	4779
Relevant Lines:	10421

---

💛 - Coveralls