chore: bump asyncpg from 0.29.0 to 0.31.0

Bumps [asyncpg](https://github.com/MagicStack/asyncpg) from 0.29.0 to 0.31.0.
- [Release notes](https://github.com/MagicStack/asyncpg/releases)
- [Commits](MagicStack/asyncpg@v0.29.0...v0.31.0)

---
updated-dependencies:
- dependency-name: asyncpg
  dependency-version: 0.31.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

backend/requirements.txt

@@ -7,7 +7,7 @@ python-multipart==0.0.22
 sqlalchemy==2.0.23
 alembic==1.12.1
 psycopg2-binary==2.9.11
-asyncpg==0.29.0
+asyncpg==0.31.0
 aiosqlite==0.19.0
 
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