Bump sqlalchemy[asyncio] from 2.0.19 to 2.0.21

Bumps [sqlalchemy[asyncio]](https://github.com/sqlalchemy/sqlalchemy) from 2.0.19 to 2.0.21.
- [Release notes](https://github.com/sqlalchemy/sqlalchemy/releases)
- [Changelog](https://github.com/sqlalchemy/sqlalchemy/blob/main/CHANGES.rst)
- [Commits](https://github.com/sqlalchemy/sqlalchemy/commits)

---
updated-dependencies:
- dependency-name: sqlalchemy[asyncio]
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

requirements.txt

@@ -1,6 +1,6 @@
 wheel==0.41.1
 asyncpg==0.28.0
-sqlalchemy[asyncio]==2.0.19
+sqlalchemy[asyncio]==2.0.21
 typing_extensions==4.7.1
 discord.py==2.3.2
 click==8.1.6