Update dependency jinja2 to v3

Author: renovate-bot

Diff for: requirements.txt

@@ -5,7 +5,7 @@ flask-wtf==0.15.1
 flask==1.1.2; (python_version >= "2.7" and python_full_version < "3.0.0") or (python_full_version >= "3.5.0")
 idna==3.1; python_version >= "3.4"
 itsdangerous==1.1.0; python_version >= "2.7" and python_full_version < "3.0.0" or python_full_version >= "3.5.0"
-jinja2==2.11.3; python_version >= "2.7" and python_full_version < "3.0.0" or python_full_version >= "3.5.0"
+jinja2==3.1.1; python_version >= "2.7" and python_full_version < "3.0.0" or python_full_version >= "3.5.0"
 markupsafe==1.1.1; python_version >= "2.7" and python_full_version < "3.0.0" or python_full_version >= "3.5.0"
 python-dotenv==0.17.1
 uwsgi==2.0.20