[SW-295] Remove default static secret key from the base settings

[kiwicomplatform]

The-zoo is vulnerable to a cryptography issue since the Django's SECRET_KEY in settings.py variable will fallback to mucho secretto if no SECRET_KEY environment variable is provided when deploying the webserver.

Steps To Reproduce:

• Deploy the-zoo without providing a SECRET_KEY environment variable
• Django's SECRET_KEY will default to mucho secretto as per line 79 in settings.py

Vulnerable line: SECRET_KEY = env("SECRET_KEY", default="mucho secretto")

Impact:

Running Django with a known SECRET_KEY defeats many of Django’s security protections, and can lead to privilege escalation and remote code execution vulnerabilities.

Remediation:

Preventing the start or generating a random key for every run might be a better practice

[aexvir]

🤔 Duplicate of #264