Gateway: update keycloak auth

[IceKhan13]

Steps to reproduce the problem

#954

Keycloak is no longer a provider in django allauth https://github.com/pennersr/django-allauth/blob/fdd5c3bdf0ebc2b471d491f9d06f01eb541bce68/docs/socialaccount/providers/keycloak.rst#L2

What is the current behavior?

Traceback (most recent call last):
  File "/home/runner/work/quantum-serverless/quantum-serverless/gateway/.tox/lint/lib/python3.9/site-packages/pylint_django/checkers/foreign_key_strings.py", line 114, in open
    django.setup()
  File "/home/runner/work/quantum-serverless/quantum-serverless/gateway/.tox/lint/lib/python3.9/site-packages/django/__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/home/runner/work/quantum-serverless/quantum-serverless/gateway/.tox/lint/lib/python3.9/site-packages/django/apps/registry.py", line 91, in populate
    app_config = AppConfig.create(entry)
  File "/home/runner/work/quantum-serverless/quantum-serverless/gateway/.tox/lint/lib/python3.9/site-packages/django/apps/config.py", line 193, in create
    import_module(entry)
  File "/opt/hostedtoolcache/Python/3.9.18/x64/lib/python3.9/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
  File "<frozen importlib._bootstrap>", line 984, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'allauth.socialaccount.providers.keycloak'

What is the expected behavior?

We decided to sunset Keycloak from our project:

• Create a custom authentication process for a debug user
• Remove (default) JWT authentication from gateway and update tests and docs that they must be using it
• Remove Keycloak from the project

[Tansito]

Trying to update keycloak's helm package I discovered an interesting conflict:

• Docker version 21 is not compatible with our current configuration
• Same for dj-rest & django-allauth packages (we already knew this last one as this issue points out).

It's a bit tricky because we could have a compatibility problem from different parts. I will try to solve this for next week. Maybe I will need your help @akihikokuroda , @IceKhan13 .

Ref: #1125

[Tansito]

After internal discussion between @akihikokuroda , @IceKhan13 , @psschwei and I, we decided to take the next steps:

• Drop support for Keycloak
• Implement a mock to support some kind of authentication for tests and local development without the need to use IQP Token
• Improve our current support for OpenID protocol (low priority task)

[IceKhan13]

xref: #1131

[IceKhan13]

Keycloak dropped in #1131 and #1134