`px.timeline` with a Daylight Savings Time scenario - missing/extra hour

Problem:
When using px.timeline on a range where a Daylight Savings Time switch occurs & time zones are in the timestamps, I observe an unexpectedly shorter/longer duration of the bar.

Example A - March - missing an hour

import pandas as pd
import plotly.express as px

df = pd.DataFrame(dict(
    x_start=[
        pd.Timestamp("2024-03-09", tz="US/Pacific"),
        pd.Timestamp("2024-03-10", tz="US/Pacific"),
        pd.Timestamp("2024-03-11", tz="US/Pacific"),
    ],
    x_end=[
        pd.Timestamp("2024-03-10", tz="US/Pacific"),
        pd.Timestamp("2024-03-11", tz="US/Pacific"),
        pd.Timestamp("2024-03-12", tz="US/Pacific"),
    ],
    y=[1, 1, 1],
))

px.timeline(df, x_start="x_start", x_end="x_end", y="y")

As you can see, for the DST day (March 10, 2024), the end date is unexpectedly 1 hour early, unlike the other days.

Example B - November - extra hour

import pandas as pd
import plotly.express as px

df = pd.DataFrame(dict(
    x_start=[
        pd.Timestamp("2023-11-05", tz="US/Pacific"),
    ],
    x_end=[
        pd.Timestamp("2023-11-06", tz="US/Pacific"),
    ],
    y=[1],
))

px.timeline(df, x_start="x_start", x_end="x_end", y="y")

In this example, 1 hour is unexpectedly added to the end.

Testing environment:

• Google Colab (also experienced on VS Code & html)
• Latest version of plotly (5.22.0).

Start by reproducing both pandas and px.timeline examples from the issue, covering the March and November DST transitions. Trace the px.timeline entry point through its handling of timezone-aware timestamps and add regression coverage for both cases. Done means each bar spans the intended local calendar interval without a missing or extra hour.