Hoist itertools dependency to workspace level (#8417)

This PR hoists the `itertools` dependency to the workspace level.

Release Notes:

- N/A

crates/breadcrumbs/Cargo.toml

@@ -13,7 +13,7 @@ doctest = false
 collections.workspace = true
 editor.workspace = true
 gpui.workspace = true
-itertools = "0.10"
+itertools.workspace = true
 language.workspace = true
 outline.workspace = true
 project.workspace = true