Duplicate release notes in multiple cAdvisor releases

Several cAdvisor GitHub releases appear to contain duplicated release notes.

Examples:

- https://github.com/google/cadvisor/releases/tag/v0.60.2
- https://github.com/google/cadvisor/releases/tag/v0.60.1
- https://github.com/google/cadvisor/releases/tag/v0.60.0
- https://github.com/google/cadvisor/releases/tag/v0.57.0
- https://github.com/google/cadvisor/releases/tag/v0.56.2

Observed behavior:

For multiple releases, the generated release-notes content is duplicated. For example, the following sections appear twice:

- `What's Changed`
- the list of merged PRs
- `New Contributors` where applicable
- `Full Changelog: ...`

Expected behavior:

Each release should contain the generated release notes only once.

This looks like an issue in the release-notes generation or release publishing process rather than an issue with cAdvisor code itself.

It may be worth checking the release automation/workflow to ensure the generated notes are not appended twice when publishing a GitHub Release.

Inspect cAdvisor's release automation/workflow and compare it with the listed GitHub Releases, starting with v0.60.2 and v0.60.1. Trace how generated notes are added during publishing, then verify that a release contains one What's Changed section, one merged-PR list, one New Contributors section where applicable, and one Full Changelog link.

Written by the indexing model from the issue text.