Update itertools requirement from 0.11.0 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@v0.11.0...v0.12.1)

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

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

subroutines/Cargo.toml

@@ -14,7 +14,7 @@ ark-serialize =  { version = "^0.4.0", default-features = false }
 ark-std = { version = "^0.4.0", default-features = false }
 derivative = { version = "2", features = ["use_core"] }
 displaydoc = { version = "0.2.3", default-features = false }
-itertools = { version = "0.11.0", optional = true }
+itertools = { version = "0.12.1", optional = true }
 rand_chacha = { version = "0.3.0", default-features = false }
 rayon = { version = "1.5.2", default-features = false, optional = true }
 transcript = { path = "../transcript" }