Bug: Wrong FIXTURE_DIR lets GeoNode fail to start

[ridoo]

Bug Description

PR #49 has an issue as it configures a wrong FIXTURE_DIR. See here

https://github.com/zalf-rdm/geonode-k8s/pull/50/files#r1288372585

Reproduction Steps

Apply Helm Config and see geonode fails to start with

*** Operational MODE: preforking ***
Traceback (most recent call last):
  File "/usr/src/geonode/./geonode/wsgi.py", line 29, in <module>
    application = get_wsgi_application()
  File "/usr/local/lib/python3.10/dist-packages/django/core/wsgi.py", line 12, in get_wsgi_application
    django.setup(set_prefix=False)
  File "/usr/local/lib/python3.10/dist-packages/django/__init__.py", line 19, in setup
    configure_logging(settings.LOGGING_CONFIG, settings.LOGGING)
  File "/usr/local/lib/python3.10/dist-packages/django/conf/__init__.py", line 82, in __getattr__
    self._setup(name)
  File "/usr/local/lib/python3.10/dist-packages/django/conf/__init__.py", line 69, in _setup
    self._wrapped = Settings(settings_module)
  File "/usr/local/lib/python3.10/dist-packages/django/conf/__init__.py", line 170, in __init__
    mod = importlib.import_module(self.SETTINGS_MODULE)
  File "/usr/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "/usr/src/geonode/./geonode/settings.py", line 2333
    FIXTURE_DIRS: [ /usr/src/geonode/fixtures ]
                    ^
SyntaxError: invalid syntax
unable to load app 0 (mountpoint='') (callable not found or import error)
*** no app loaded. GAME OVER ***
2023/08/09 11:59:17 Command exited with error: exit status 22

Behavior

GeoNode starts without an issue

Additional Information

Any additional information or context that may be helpful in resolving the bug.