tests: Fix Replacement Policy Tests

The script run by 'test_replacement_policies.py' was named
'run_replacement_policy_test.py'. This caused the TestLib framework to
fail as any file with the string "test" in it was attempted to parse as
a test. As this is a gem5 Python config file, this caused a failure.

To fix this the file was renamed 'run_replacement_policy.py'.

Change-Id: I6f0a09e4f5056a9c94e258c9aea26bf277206733
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/69237
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>

tests/gem5/replacement-policies/test_replacement_policies.py

@@ -45,7 +45,7 @@ def test_replacement_policy(config_name: str, config_path: str) -> None:
             "tests",
             "gem5",
             "replacement-policies",
-            "run_replacement_policy_test.py",
+            "run_replacement_policy.py",
         ),
         config_args=[config_name, config_path],
         valid_isas=(constants.null_tag,),