Update dependency django-environ to v0.9.0

This MR contains the following updates:

Package	Type	Update	Change
django-environ (source, changelog)	dependencies	minor	0.8.1 -> 0.9.0

---

Release Notes

joke2k/django-environ

v0.9.0

Compare Source

Added +++++

• Added support for Postgresql cluster URI #&#8203;355 <https://github.com/joke2k/django-environ/pull/355>_.
• Added support for Django 4.0 #&#8203;371 <https://github.com/joke2k/django-environ/issues/371>_.
• Added support for prefixed variables #&#8203;362 <https://github.com/joke2k/django-environ/issues/362>_.
• Amended documentation.

Deprecated ++++++++++

• Env.unicode() is deprecated and will be removed in the next major release. Use Env.str() instead.

Changed +++++++

• Attach cause to ImproperlyConfigured exception #&#8203;360 <https://github.com/joke2k/django-environ/issues/360>_.

Fixed +++++

• Fixed _cast_urlstr unquoting #&#8203;357 <https://github.com/joke2k/django-environ/issues/357>_.
• Fixed documentation regarding unsafe characters in URLs #&#8203;220 <https://github.com/joke2k/django-environ/issues/220>_.
• Fixed environ.Path.__eq__() to compare paths correctly #&#8203;86 <https://github.com/joke2k/django-environ/issues/86>, #&#8203;197 <https://github.com/joke2k/django-environ/issues/197>.

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever MR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this MR and you won't be reminded about this update again.

---

• If you want to rebase/retry this MR, check this box

---

This MR has been generated by Renovate Bot.