build(deps): bump atom_syndication from 0.12.2 to 0.12.3

Bumps [atom_syndication](https://github.com/rust-syndication/atom) from 0.12.2 to 0.12.3.
- [Release notes](https://github.com/rust-syndication/atom/releases)
- [Changelog](https://github.com/rust-syndication/atom/blob/master/CHANGELOG.md)
- [Commits](rust-syndication/atom@0.12.2...0.12.3)

---
updated-dependencies:
- dependency-name: atom_syndication
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>