pw_unit_test/test_runner: Only debug log on success

Updates the pw_unit_test/test_runner.py and pw_cli/process.py to
ensure that a successful host unit test run does not produce extra
ninja output when using CMake by using debug logs instead of info
logs for successful runs.

Change-Id: I463550854cbc534b52ed2c29e3ea7e763939010f
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/126846
Reviewed-by: Taylor Cramer <cramertj@google.com>
Pigweed-Auto-Submit: Ewout van Bekkum <ewout@google.com>
Reviewed-by: Wyatt Hepler <hepler@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/pw_cli/py/pw_cli/process.py b/pw_cli/py/pw_cli/process.py
index d30ed94..e683db8 100644
--- a/pw_cli/py/pw_cli/process.py
+++ b/pw_cli/py/pw_cli/process.py
@@ -129,7 +129,7 @@
     if process.returncode:
         _LOG.error('%s exited with status %d', program, process.returncode)
     else:
-        _LOG.info('%s exited successfully', program)
+        _LOG.debug('%s exited successfully', program)
 
     return CompletedProcess(process, output)
 
diff --git a/pw_unit_test/py/pw_unit_test/test_runner.py b/pw_unit_test/py/pw_unit_test/test_runner.py
index b5c660e..bc88f99 100644
--- a/pw_unit_test/py/pw_unit_test/test_runner.py
+++ b/pw_unit_test/py/pw_unit_test/test_runner.py
@@ -185,7 +185,7 @@
             total = str(len(self._tests))
             test_counter = f'Test {idx:{len(total)}}/{total}'
 
-            _LOG.info('%s: [ RUN] %s', test_counter, test.name)
+            _LOG.debug('%s: [ RUN] %s', test_counter, test.name)
 
             # Convert POSIX to native directory seperators as GN produces '/'
             # but the Windows test runner needs '\\'.