Re-enable user-defined timestamp and subcompactions (#10689)

Summary:
Hopefully, we can re-enable the combination of user-defined timestamp and subcompactions
after https://github.com/facebook/rocksdb/issues/10658.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10689

Test Plan:
Make sure the following succeeds on devserver.
make crash_test_with_ts

Reviewed By: ltamasi

Differential Revision: D39556558

Pulled By: riversand963

fbshipit-source-id: 4695f420b1bc9ebf3b24640b693746f4db82c149

tools/db_crashtest.py

@@ -368,12 +368,6 @@ ts_params = {
     "enable_blob_files": 0,
     "use_blob_db": 0,
     "ingest_external_file_one_in": 0,
-    # TODO akanksha: Currently subcompactions is failing with user_defined_timestamp if
-    # subcompactions > 1, or
-    # compact_pri == 4 even if subcompactions is 1, there can still be multiple subcompactions.
-    # Remove this check once its fixed.
-    "subcompactions": 1,
-    "compaction_pri": random.randint(0, 3),
 }
 
 tiered_params = {