exp run: clean untracked lockfiles before running (#5426)

* exp run/reset: clean untracked lockfiles

* update log level for run -f/--force message

dvc/repo/experiments/__init__.py

@@ -258,9 +258,22 @@ class Experiments:
             if is_lock_file(fname)
         ]
         if lock_files:
+
             self.scm.reset(paths=lock_files)
             self.scm.checkout_index(paths=lock_files, force=True)
 
+    def _prune_untracked_lockfiles(self):
+        from dvc.dvcfile import is_lock_file
+        from dvc.utils.fs import remove
+
+        untracked = [
+            fname
+            for fname in self.scm.untracked_files()
+            if is_lock_file(fname)
+        ]
+        for fname in untracked:
+            remove(fname)
+
     def _stash_msg(
         self,
         rev: str,
@@ -698,6 +711,7 @@ class Experiments:
         # result in conflict between workspace params and stashed CLI params).
         self.scm.reset(hard=True)
         with self.scm.detach_head(entry.rev):
+            self._prune_untracked_lockfiles()
             rev = self.stash.pop()
             self.scm.set_ref(EXEC_BASELINE, entry.baseline_rev)
             if entry.branch:

dvc/repo/experiments/executor/base.py

@@ -250,7 +250,9 @@ class BaseExecutor(ABC):
             args, kwargs = cls._repro_args(dvc)
 
             repro_force = kwargs.get("force", False)
-            logger.debug("force = %s", str(repro_force))
+            logger.trace(  # type: ignore[attr-defined]
+                "Executor repro with force = '%s'", str(repro_force)
+            )
 
             # NOTE: for checkpoint experiments we handle persist outs slightly
             # differently than normal: