Remove API_BASE_URL references (#4331)

docs/setup/deployment/production/heroku.md

@@ -21,7 +21,6 @@ Then so the following steps for each environment.
 
 Set these settings as a minimum:
 
-* `API_BASE_URL`
 * `BASIC_AUTH_ENABLED`
 * `BASIC_AUTH_LOGIN`
 * `BASIC_AUTH_PASSWORD`

docs/setup/deployment/production/stand-alone.md

@@ -230,7 +230,6 @@ Here is a list of settings that can be set as environment variables or in a `hyp
 **None optional:**
 
 ```text
-API_BASE_URL:                                  https://example.org/api
 CACHE_CONTROL_MAX_AGE:                         14400
 COOKIE_SECURE:                                 true
 DJANGO_SETTINGS_MODULE:                        hypha.settings.production