Tracking issue for release notes of #128284: Stabilize offset_of_nested

[rustbot]

This issue tracks the release notes text for #128284.

• [ ] Issue is nominated for the responsible team (and T-release nomination is removed).
• [ ] Proposed text is drafted by team responsible for underlying change.
• [ ] Issue is nominated for release team review of clarity for wider audience.
• [ ] Release team includes text in release notes/blog posts.

Release notes text:

The section title will be de-duplicated by the release team with other release notes issues. Prefer to use the standard titles from previous releases. More than one section can be included if needed.

# Compatibility Notes
- [Stabilize offset_of_nested](https://github.com/rust-lang/rust/pull/128284)

Release blog section (if any, leave blank if no section is expected):