Remove TestRandom (#9006)

We  have a legacy `TestRandom` trait which generates random types for testing and fuzzing.
This function overlaps with `arbitrary` which is used very commonly in the ecosystem.


  Remove `TestRandom` and generate random type instances using `Arbitrary`.


Co-Authored-By: Mac L <mjladson@pm.me>

Co-Authored-By: Michael Sproul <michael@sigmaprime.io>

Cargo.toml

@@ -42,7 +42,6 @@ members = [
     "common/system_health",
     "common/target_check",
     "common/task_executor",
-    "common/test_random_derive",
     "common/tracing_samplers",
     "common/validator_dir",
     "common/warp_utils",
@@ -200,6 +199,7 @@ proto_array = { path = "consensus/proto_array" }
 quote = "1"
 r2d2 = "0.8"
 rand = "0.9.0"
+rand_xorshift = "0.4.0"
 rayon = "1.7"
 regex = "1"
 reqwest = { version = "0.12", default-features = false, features = ["blocking", "json", "stream", "rustls-tls"] }