fix: requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-IDNA-6597975

Author: snyk-bot

requirements.txt

@@ -4,7 +4,7 @@ cffi==1.14.0
 chardet==3.0.4
 click==7.1.1
 cryptography==3.3.2
-idna==2.9
+idna==3.7
 importlib-metadata==1.6.0
 jeepney==0.4.3
 keyring==21.2.0