Not tested: `Period.strftime` and `PeriodIndex.strftime` with non-ascii char present in the formatting string

[smarie]

EDIT : as I found out this was not a bug in the main branch, I introduced it accidentally in #46405.
Therefore I rename the ticket as "not tested", meaning that current test suite does not cover this case.

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Reproducible Example

import pandas as pd
import locale

locale.setlocale(locale.LC_ALL, "fr_FR")
per = pd.Period("2018-03-11 13:00", freq="H")
assert per.strftime("%Y é") == "2018 é"

Issue Description

When there is a non-ascii character in the formatting string passed to Period.strftime the result may be corrupted. This is most probably related to an encoding error.

Expected Behavior

The assert should pass without error

[smarie]

This issue was extracted from #46319 for clarity

[smarie]

I just realized that this bug was actually introduced in my PR #46405
There was no test for this, introducing one is the only thing new that can be done.

• Renamed accordingly
• Edited original post so that it describes the test to create