[issue35500] Align expected and actual calls on mock.assert_called_with error message

[Roundup Robot]

Change by Roundup Robot <devnull at psf.upfronthosting.co.za>:


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keywords: +patch, patch, patch, patch
pull_requests: +11815, 11816, 11817, 11818
stage: test needed -> patch review

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue35500>
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