Update dependency drf_yasg to v1.21.3

This MR contains the following updates:

Package	Update	Change
drf_yasg	minor	==1.20.0 -> ==1.21.3

---

Release Notes

axnsan12/drf-yasg

v1.21.3

Compare Source

FIXED: Set generator url for swagger_settings.DEFAULT_API_URL (#​682) FIXED: Check fields for allow_null attribute (#​688) FIXED: Encode pytz object field as a string by default (#​717) FIXED: Handle errors rendering with TemplateHTMLRenderer (#​742)

v1.21.2

Compare Source

FIXED: Fixed code block rst syntax in README.rst (#​797)

v1.21.0

Compare Source

• IMMROVED: Add utf-8 support to yaml loaders (#​692)

v1.20.3

Compare Source

• FIXED: Source mapping in redoc.min.js (#​778)
• FIXED: Publish action tag pattern in publish.yml (#​794)

---

Configuration

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

🚦 Automerge: Enabled.

♻ 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, click this checkbox.

---

This MR has been generated by Renovate Bot.