Update RELEASENOTES with bullet for previous PR

[dylan-smith]

The recent merged PR didn't include anything in the RELEASENOTES. This PR adds a blurb about the new option in gh ado2gh rewire-pipeline.

• Did you write/update appropriate tests
• Release notes updated (if appropriate)
• Appropriate logging output
• Issue linked
• Docs updated (or issue created)
• New package licenses are added to ThirdPartyNotices.txt (if applicable)

[iomekam]

Thanks for catching this!

[Copilot]

Pull Request Overview

This PR adds a missing entry to the release notes for the recently introduced CLI option.

• Adds a bullet to RELEASENOTES.md describing the new --target-api-url flag for gh ado2gh rewire-pipeline.

[github-actions]

Unit Test Results

  1 files    1 suites   21s ⏱️
898 tests 898 ✅ 0 💤 0 ❌
899 runs  899 ✅ 0 💤 0 ❌

Results for commit 467d8e8.

[github-actions]

Package	Line Rate	Branch Rate	Complexity	Health
Octoshift	87%	76%	1435	✔
bbs2gh	82%	76%	669	✔
gei	81%	73%	596	✔
ado2gh	84%	78%	633	✔
Summary	84% (7283 / 8621)	76% (1714 / 2266)	3333	✔