Update itertools requirement from 0.10.3 to 0.12.1

Updates the requirements on [itertools](https://github.com/rust-itertools/itertools) to permit the latest version.
- [Changelog](https://github.com/rust-itertools/itertools/blob/master/CHANGELOG.md)
- [Commits](rust-itertools/itertools@v0.10.3...v0.12.1)

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

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

plotly/Cargo.toml

@@ -41,7 +41,7 @@ wasm-bindgen-futures = { version = "0.4", optional = true }
 [dev-dependencies]
 csv = "1.1.6"
 image = "0.24.4"
-itertools = "0.10.3"
+itertools = "0.12.1"
 itertools-num = "0.1.3"
 ndarray = "0.15.4"
 plotly_kaleido = { version = "0.8.4", path = "../plotly_kaleido" }