upgrade ROCm to 6.4.2 (#4876)

Summary:
X-link: facebookresearch/FBGEMM#1905

Pull Request resolved: #4876

Reviewed By: ionuthristodorescu

Differential Revision: D82558237

Pulled By: q10

fbshipit-source-id: 930a30813d7aecc1f4c975bed36551b97b2caa5a

Author: q10

.github/scripts/generate_ci_matrix.py

@@ -311,9 +311,9 @@ def cuda_versions(self) -> List[str]:
 
     def rocm_versions(self) -> List[str]:
         if GitRepo.ref() == REFS_MAIN and GitRepo.event_name() == EVENT_NAME_PUSH:
-            return ["6.4"]
+            return ["6.4.2"]
         else:
-            return ["6.3", "6.4"]
+            return ["6.3", "6.4.2"]
 
     def host_machines(self) -> List[Dict[str, str]]:
         # For the list of available instance types: