show hydra dumped results in debug mode (iterative#9460)

* show hydra dumped results in debug mode

* update hydra composition trace msg

dvc/utils/hydra.py

@@ -1,3 +1,4 @@
+import logging
 from pathlib import Path
 from typing import TYPE_CHECKING, List
 
@@ -9,6 +10,9 @@
     from dvc.types import StrPath
 
 
+logger = logging.getLogger(__name__)
+
+
 def compose_and_dump(
     output_file: "StrPath",
     config_dir: str,
@@ -44,6 +48,9 @@ def compose_and_dump(
         dumper(output_file, OmegaConf.to_object(cfg))
     else:
         Path(output_file).write_text(OmegaConf.to_yaml(cfg), encoding="utf-8")
+    logger.trace(  # type: ignore[attr-defined]
+        "Hydra composition enabled. Contents dumped to %s:\n %s", output_file, cfg
+    )
 
 
 def apply_overrides(path: "StrPath", overrides: List[str]) -> None: