build(deps): update polars requirement from 0.38.1 to 0.39.1

Updates the requirements on [polars](https://github.com/pola-rs/polars) to permit the latest version.
- [Release notes](https://github.com/pola-rs/polars/releases)
- [Commits](pola-rs/polars@rs-0.38.1...rs-0.39.1)

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

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

Cargo.toml

@@ -76,7 +76,7 @@ num = { version = "0.4.1", features = ["rand"] }
 time = { version = "0.3.34", features = ["macros"] }
 
 # https://docs.rs/polars/latest/polars/
-polars = { version = "0.38.1", features = ["docs-selection"] }
+polars = { version = "0.39.1", features = ["docs-selection"] }
 
 
 [dev-dependencies]