Switch to requirements.in for python deps

backend/requirements.txt → backend/requirements.in

 APScheduler==3.9.1
-attrs==21.4.0
-black==22.1.0
-certifi==2021.10.8
-cffi==1.15.0
 charset-normalizer==2.0.12
+# CLI creation kit
 click==8.0.4
-cryptography==36.0.2
 Flask==2.0.3
 Flask-Cors==3.0.10
 flask-expects-json==1.7.0
 Flask-JWT-Extended==4.3.1
 Flask-Migrate==4.0.1
 Flask-SQLAlchemy==2.5.1
-gunicorn==20.1.0
-idna==3.3
 pip-install==1.3.5
-itsdangerous==2.1.1
 jsonschema==4.4.0
 Jinja2==3.0.3
 jinja2-base64-filters==0.1.4
 kubernetes==24.2.0
-MarkupSafe==2.1.1
-mypy-extensions==0.4.3
 NamedAtomicLock==1.1.3
 oauthlib==3.2.0
 ory-kratos-client==1.0.0
 ory-hydra-client==1.11.8
-pathspec==0.9.0
-platformdirs==2.5.1
 posix-ipc==1.1.1
-pycparser==2.21
-PyJWT==2.3.0
-pymysql==1.0.2
-pyrsistent==0.18.1
 PyYAML==6.0.1
 regex==2022.3.15
 requests==2.27.1
 requests-oauthlib==1.3.1
-six==1.16.0
-tomli==1.2.3
-typing-extensions==4.1.1
-urllib3==1.26.8
-Werkzeug==2.0.3