PC-1294: Fix CSRF Fail

[samyou-softwire]

Link to Jira ticket

Description

specify CSRF_TRUSTED_ORIGINS environment variable

use the BASE_URL environment variable to make this work across environments

missed in django upgrade. see https://docs.djangoproject.com/en/5.1/releases/4.0/#csrf

Checklist

• I have made any necessary updates to the documentation
• I have checked there are no unnecessary IDE warnings in this PR
• I have checked there are no unintentional line ending changes
• I have added tests where applicable
• If I have made any changes to the code, I have used the IDE auto-formatter on it
• If I have made any changes to Python files (even if not changing any content strings), I have run make extract-translations

[jdgage]

Assume this all works fine locally?

[samyou-softwire]

Assume this all works fine locally?

yep, though not convinced the CSRF origin is checked locally anyway