settings: Move INTERNAL_IPS config to top level

When running in debug mode, it is necessary to have the INTERNAL_IPS variable
properly set in order to have some functionality.

Before we were assuming that it was only necessary for the Django toolbar,
however, according the documentation [1] it is also necessary for exposing some
variables in the template context, which is something we are going to need in
the future.

1: https://docs.djangoproject.com/en/3.2/ref/settings/#internal-ips

promgen/settings.py

@@ -40,6 +40,9 @@
 # SECURITY WARNING: don't run with debug turned on in production!
 DEBUG = env.bool("DEBUG", default=False)
 
+if DEBUG:
+    INTERNAL_IPS = ["127.0.0.1"]
+
 # Settings for Prometheus paths and such
 if PROMGEN_CONFIG_FILE.exists():
     with PROMGEN_CONFIG_FILE.open() as fp:
@@ -210,7 +213,6 @@
     import debug_toolbar  # NOQA
 
     INSTALLED_APPS += ["debug_toolbar"]
-    INTERNAL_IPS = ["127.0.0.1"]
 except ImportError:
     MIDDLEWARE.remove("debug_toolbar.middleware.DebugToolbarMiddleware")