Fix De Lijn 'tzinfo' error (#73502)

* Fix De Lijn component tzinfo error

This fix should update the issue "Error:'str' object has no attribute 'tzinfo'" (issue #67455)

* fix Black and isort errors

fixing errors from Black and isort CI validation

* Fix black and flake8 issues

Fixing black and flake8 issues to pass CI

homeassistant/components/delijn/sensor.py

@@ -1,6 +1,7 @@
 """Support for De Lijn (Flemish public transport) information."""
 from __future__ import annotations
 
+from datetime import datetime
 import logging
 
 from pydelijn.api import Passages
@@ -111,7 +112,9 @@ class DeLijnPublicTransportSensor(SensorEntity):
             first = self.line.passages[0]
             if (first_passage := first["due_at_realtime"]) is None:
                 first_passage = first["due_at_schedule"]
-            self._attr_native_value = first_passage
+            self._attr_native_value = datetime.strptime(
+                first_passage, "%Y-%m-%dT%H:%M:%S%z"
+            )
 
             for key in AUTO_ATTRIBUTES:
                 self._attr_extra_state_attributes[key] = first[key]