Re-export itertools from tuwunel_core crate.

Signed-off-by: Jason Volk <jason@zemos.net>

Cargo.lock

@@ -5151,7 +5151,6 @@ dependencies = [
  "http-body-util",
  "hyper",
  "ipaddress",
- "itertools 0.14.0",
  "log",
  "rand 0.8.5",
  "reqwest",
@@ -5237,7 +5236,6 @@ dependencies = [
  "criterion",
  "ctor",
  "futures",
- "itertools 0.14.0",
  "log",
  "minicbor",
  "minicbor-serde",
@@ -5309,7 +5307,6 @@ dependencies = [
  "http",
  "image",
  "ipaddress",
- "itertools 0.14.0",
  "ldap3",
  "log",
  "loole",