Bump karton-core from 5.4.0 to 5.5.0 (#1300)

Bumps [karton-core](https://github.com/CERT-Polska/karton) from 5.4.0 to 5.5.0.
- [Release notes](https://github.com/CERT-Polska/karton/releases)
- [Changelog](https://github.com/CERT-Polska/karton/blob/master/docs/breaking_changes.rst)
- [Commits](CERT-Polska/karton@v5.4.0...v5.5.0)

---
updated-dependencies:
- dependency-name: karton-core
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements.txt

@@ -15,7 +15,7 @@ freezegun==1.5.1
 h11==0.14.0
 idna==3.10
 Jinja2==3.1.4
-karton-core==5.4.0
+karton-core==5.5.0
 git+https://github.com/CERT-Polska/mailgoose@v1.3.4#egg=libmailgoose&subdirectory=scan
 liccheck==0.9.2
 Markdown==3.7