Bump dnspython from 2.3.0 to 2.6.1 in /lib/chatsecure

Bumps [dnspython](https://github.com/rthalley/dnspython) from 2.3.0 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@v2.3.0...v2.6.1)

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

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

lib/chatsecure/requirements.txt

@@ -6,7 +6,7 @@ cffi==1.15.1
 charset-normalizer==3.1.0
 click==8.1.3
 cryptography==42.0.4
-dnspython==2.3.0
+dnspython==2.6.1
 eventlet==0.35.2
 exceptiongroup==1.1.1
 Flask==2.2.5