tests (device_config): experiment with output format

Output file level errors against line 1.

Github is picking up the errors now in the checks view, but is not
showing the file level errors in the PR source diff view.

tests/test_device_config.py

@@ -521,24 +521,28 @@ class TestDeviceConfig(IsolatedAsyncioTestCase):
             try:
                 YAML_SCHEMA(parsed._config)
             except vol.MultipleInvalid as e:
-                self.fail(f"\n::error file={fname}::Validation error in {cfg}: {e}")
+                self.fail(
+                    f"\n::error file={fname},line=1::Validation error in {cfg}: {e}"
+                )
 
             self.assertIsNotNone(
                 parsed._config.get("name"),
-                f"\n::error file={fname}::name missing from {cfg}",
+                f"\n::error file={fname},line=1::name missing from {cfg}",
             )
             count = 0
             for entity in parsed.all_entities():
                 self.check_entity(entity, cfg)
                 entities.append(entity.config_id)
                 count += 1
-            assert count > 0, f"\n::error file={fname}::No entities found in {cfg}"
+            assert count > 0, (
+                f"\n::error file={fname},line=1::No entities found in {cfg}"
+            )
 
             # check entities are unique
             self.assertCountEqual(
                 entities,
                 set(entities),
-                f"\n::error file={fname}::Duplicate entities in {cfg}",
+                f"\n::error file={fname},line=1::Duplicate entities in {cfg}",
             )
 
     def test_configs_can_be_matched(self):
@@ -568,14 +572,14 @@ class TestDeviceConfig(IsolatedAsyncioTestCase):
             self.assertGreater(
                 len(required),
                 0,
-                msg=f"\n::error file={fname}::No required dps found in {cfg}",
+                msg=f"\n::error file={fname},line=1::No required dps found in {cfg}",
             )
 
             for dp in required:
                 self.assertNotIn(
                     dp,
                     optional,
-                    msg=f"\n::error file={fname}::Optional dp {dp} is required in {cfg}",
+                    msg=f"\n::error file={fname},line=1::Optional dp {dp} is required in {cfg}",
                 )
 
     # Most of the device_config functionality is exercised during testing of