build(deps): bump sqlx from 0.5.13 to 0.6.0 in /atcoder-problems-backend

Bumps [sqlx](https://github.com/launchbadge/sqlx) from 0.5.13 to 0.6.0.
- [Release notes](https://github.com/launchbadge/sqlx/releases)
- [Changelog](https://github.com/launchbadge/sqlx/blob/main/CHANGELOG.md)
- [Commits](launchbadge/sqlx@v0.5.13...v0.6.0)

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

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

Author: dependabot[bot]

atcoder-problems-backend/Cargo.lock

@@ -8,7 +8,7 @@ publish = false
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-sqlx = { version = "0.5.13", features = ["postgres", "runtime-tokio-rustls"] }
+sqlx = { version = "0.6.0", features = ["postgres", "runtime-tokio-rustls"] }
 async-trait = "0.1.56"
 serde = { version = "1.0", features = ["derive"] }
 uuid = { version = "1.1", features = ["serde", "v4"] }