Update python-dotenv requirement in /telegram_bot

Updates the requirements on [python-dotenv](https://github.com/theskumar/python-dotenv) to permit the latest version.
- [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/v0.20.0...v0.21.0)

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

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

frontend/package.json

@@ -30,7 +30,7 @@
   },
   "devDependencies": {
     "@angular-devkit/build-angular": "~13.3.5",
-    "@angular-eslint/builder": "14.0.4",
+    "@angular-eslint/builder": "13.2.1",
     "@angular-eslint/eslint-plugin": "13.2.1",
     "@angular-eslint/eslint-plugin-template": "13.2.1",
     "@angular-eslint/schematics": "13.2.1",

telegram_bot/requirements.txt

@@ -1,7 +1,7 @@
 pyTelegramBotAPI~=4.5.0
 Markdown~=3.3.6
 newsapi-python~=0.2.6
-python-dotenv~=0.20.0
+python-dotenv~=0.21.0
 requests~=2.27.1
 APScheduler~=3.9.1
 croniter~=1.3.4