Update itertools requirement from 0.12 to 0.13

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@v0.12.0...v0.13.0)

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

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

ip_proofs/Cargo.toml

@@ -22,7 +22,7 @@ ark-std = "0.4"
 ark-groth16 = "0.4"
 digest = "0.9"
 num-traits = "0.2"
-itertools = "0.12"
+itertools = "0.13"
 rayon = { version = "1", optional = true }
 
 ark-inner-products = { path = "../inner_products" }