chore(deps): bump asyncpg in /reference-apps/fastapi-api-first

Bumps [asyncpg](https://github.com/MagicStack/asyncpg) from 0.30.0 to 0.31.0.
- [Release notes](https://github.com/MagicStack/asyncpg/releases)
- [Commits](MagicStack/asyncpg@v0.30.0...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]

reference-apps/fastapi-api-first/requirements.txt

@@ -12,7 +12,7 @@ pybreaker==1.4.1  # Circuit breaker
 httpx==0.28.1
 
 # Database drivers (versions must match code-first for compatibility)
-asyncpg==0.30.0
+asyncpg==0.31.0
 aiomysql==0.3.2
 cryptography>=41.0.0  # Required for MySQL caching_sha2_password auth
 motor==3.7.1