Remove debug print statements from unittest adapter output (#25854)

`PROJECT_ROOT_PATH is set, using /... as cwd for execution payload` is
printed to stdout during unittest discovery and execution, leaking into
the Test Results panel.

- Remove `print()` in `python_files/unittestadapter/execution.py`
(execution path)
- Remove `print()` in `python_files/unittestadapter/discovery.py`
(discovery path)

All functional logic (reading the env var, setting `top_level_dir`,
updating the global) is unchanged.

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python_files/unittestadapter/discovery.py

@@ -146,9 +146,6 @@ def discover_tests(
         project_root_path = os.environ.get("PROJECT_ROOT_PATH")
         if project_root_path:
             top_level_dir = project_root_path
-            print(
-                f"PROJECT_ROOT_PATH is set, using {project_root_path} as top_level_dir for discovery"
-            )
 
         # Perform regular unittest test discovery.
         # Pass project_root_path so the payload's cwd matches the project root.

python_files/unittestadapter/execution.py

@@ -373,9 +373,6 @@ def send_run_data(raw_data, test_run_pipe):
             # Update the module-level variable for send_run_data to use
             # pylint: disable=global-statement
             globals()["PROJECT_ROOT_PATH"] = project_root_path
-            print(
-                f"PROJECT_ROOT_PATH is set, using {project_root_path} as cwd for execution payload"
-            )
 
         # Perform regular unittest execution.
         # Pass project_root_path so the payload's cwd matches the project root.