build(deps): bump systemd/mkosi

Bumps [systemd/mkosi](https://github.com/systemd/mkosi) from 854881dffca6b8ee53c3ccd57c1401f7b3101a88 to 5f39f28f91c9401572e34f7bc8e23cee53531388.
- [Release notes](https://github.com/systemd/mkosi/releases)
- [Commits](systemd/mkosi@854881d...5f39f28)

---
updated-dependencies:
- dependency-name: systemd/mkosi
  dependency-version: 5f39f28f91c9401572e34f7bc8e23cee53531388
  dependency-type: direct:production
...

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -25,7 +25,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
-      - uses: systemd/mkosi@854881dffca6b8ee53c3ccd57c1401f7b3101a88
+      - uses: systemd/mkosi@5f39f28f91c9401572e34f7bc8e23cee53531388
       - name: Build RPM
         run: mkosi
       - name: Verify RPM contents