Update datafusion requirement from 38 to 40

Updates the requirements on [datafusion](https://github.com/apache/datafusion) to permit the latest version.
- [Changelog](https://github.com/apache/datafusion/blob/main/CHANGELOG.md)
- [Commits](apache/datafusion@38.0.0...40.0.0)

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

Signed-off-by: dependabot[bot] <support@github.com>

convergence-arrow/Cargo.toml

@@ -10,7 +10,7 @@ repository = "https://github.com/returnString/convergence"
 [dependencies]
 tokio = { version = "1" }
 async-trait = "0.1"
-datafusion = "38"
+datafusion = "40"
 convergence = { path = "../convergence", version = "0.16.0" }
 chrono = "0.4"