build(deps): update dunamai requirement from ~=1.16.1 to ~=1.21.2

Updates the requirements on [dunamai](https://github.com/mtkennerly/dunamai) to permit the latest version.
- [Release notes](https://github.com/mtkennerly/dunamai/releases)
- [Changelog](https://github.com/mtkennerly/dunamai/blob/master/CHANGELOG.md)
- [Commits](mtkennerly/dunamai@v1.16.1...v1.21.2)

---
updated-dependencies:
- dependency-name: dunamai
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

requirements.txt

@@ -1,4 +1,4 @@
-dunamai~=1.16.1
+dunamai~=1.21.2
 meson~=1.3.0
 ninja
 kconfiglib~=14.1.0