Bump python-dotenv in /_code-samples/delete-account/py

Bumps [python-dotenv](https://github.com/theskumar/python-dotenv) from 1.2.1 to 1.2.2.
- [Release notes](https://github.com/theskumar/python-dotenv/releases)
- [Changelog](https://github.com/theskumar/python-dotenv/blob/main/CHANGELOG.md)
- [Commits](https://github.com/theskumar/python-dotenv/compare/v1.2.1...v1.2.2)

---
updated-dependencies:
- dependency-name: python-dotenv
  dependency-version: 1.2.2
  dependency-type: direct:production
...

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

_code-samples/delete-account/py/requirements.txt

@@ -1,2 +1,2 @@
 xrpl-py==4.5.0
-python-dotenv==1.2.1
+python-dotenv==1.2.2