MNT: Fix double evaluation of _LazyTickList

Closes matplotlib#28908.

It seems the read-access to `instance.majorTicks` per `instance
.majorTicks.append()` still triggers the descriptor, even though
`instance.majorTicks = []` previously should have rebound the name. For
details see matplotlib#28908.

Author: timhoffm

lib/matplotlib/axis.py

@@ -543,12 +543,12 @@ def __get__(self, instance, owner):
             if self._major:
                 instance.majorTicks = []
                 tick = instance._get_tick(major=True)
-                instance.majorTicks.append(tick)
+                instance.majorTicks = [tick]
                 return instance.majorTicks
             else:
                 instance.minorTicks = []
                 tick = instance._get_tick(major=False)
-                instance.minorTicks.append(tick)
+                instance.minorTicks = [tick]
                 return instance.minorTicks