Small speed up to creating stats database rows (#124587)

* Small speed up to creating stats database rows

Calling .timestamp() directly is faster on new cpython

* more cleanup

homeassistant/components/recorder/db_schema.py

@@ -693,13 +693,13 @@ class StatisticsBase:
 
     @classmethod
     def from_stats(cls, metadata_id: int, stats: StatisticData) -> Self:
-        """Create object from a statistics with datatime objects."""
+        """Create object from a statistics with datetime objects."""
         return cls(  # type: ignore[call-arg]
             metadata_id=metadata_id,
             created=None,
             created_ts=time.time(),
             start=None,
-            start_ts=dt_util.utc_to_timestamp(stats["start"]),
+            start_ts=stats["start"].timestamp(),
             mean=stats.get("mean"),
             min=stats.get("min"),
             max=stats.get("max"),

homeassistant/components/recorder/models/time.py

@@ -65,9 +65,7 @@ def process_datetime_to_timestamp(ts: datetime) -> float:
 
 def datetime_to_timestamp_or_none(dt: datetime | None) -> float | None:
     """Convert a datetime to a timestamp."""
-    if dt is None:
-        return None
-    return dt_util.utc_to_timestamp(dt)
+    return None if dt is None else dt.timestamp()
 
 
 def timestamp_to_datetime_or_none(ts: float | None) -> datetime | None: