Bump dnspython from 2.1.0 to 2.6.1

Bumps [dnspython](https://github.com/rthalley/dnspython) from 2.1.0 to 2.6.1.
- [Release notes](https://github.com/rthalley/dnspython/releases)
- [Changelog](https://github.com/rthalley/dnspython/blob/main/doc/whatsnew.rst)
- [Commits](rthalley/dnspython@v2.1.0...v2.6.1)

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

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

requirements-dev.txt

@@ -5,4 +5,4 @@ coverage
 pre-commit
 safety
 bandit
-dnspython==2.1.0
+dnspython==2.6.1

requirements.txt

@@ -19,7 +19,7 @@ reportlab==4.0.4  # debrief
 rich==13.7.0
 svglib==1.5.1  # debrief
 Markdown==3.4.4  # training
-dnspython==2.4.2
+dnspython==2.6.1
 asyncssh==2.14.1
 aioftp~=0.20.0
 packaging==23.2