Bump dnspython from 2.3.0 to 2.6.1 in /mongodb

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>

mongodb/requirements.txt

@@ -1,7 +1,7 @@
 annotated-types==0.5.0
 certifi==2023.7.22
 charset-normalizer==3.1.0
-dnspython==2.3.0
+dnspython==2.6.1
 docker==6.1.3
 idna==3.4
 packaging==23.1