Build(deps): update sqlx requirement from 0.7 to 0.8

Updates the requirements on [sqlx](https://github.com/launchbadge/sqlx) to permit the latest version.
- [Changelog](https://github.com/launchbadge/sqlx/blob/main/CHANGELOG.md)
- [Commits](launchbadge/sqlx@v0.7.0...v0.8.1)

---
updated-dependencies:
- dependency-name: sqlx
  dependency-type: direct:production
...

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

Cargo.toml

@@ -10,7 +10,7 @@ readme= "README.md"
 
 [dependencies]
 casbin = { version = "2.1.0", default-features = false }
-sqlx = { version = "0.7", default-features = false, features = [ "macros" ] }
+sqlx = { version = "0.8", default-features = false, features = [ "macros" ] }
 async-trait = "0.1.51"
 dotenv = { version = "0.15.0", default-features = false }
 tokio = { version = "1.10.0", default-features = false, optional = true }