build(deps): bump nonebot-plugin-alconna from 0.45.4 to 0.50.2

Bumps [nonebot-plugin-alconna](https://github.com/nonebot/plugin-alconna) from 0.45.4 to 0.50.2.
- [Release notes](https://github.com/nonebot/plugin-alconna/releases)
- [Commits](nonebot/plugin-alconna@v0.45.4...v0.50.2)

---
updated-dependencies:
- dependency-name: nonebot-plugin-alconna
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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