Revert "WIP: patches/python: override py3 builtin round to keep py2 behavior."

This reverts commit aeb16d3d.

Let's see test status without this
20 jobs for zope4py3 in 0 seconds
Status Job ID Name Coverage
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failed ERP5.CodingStyleTest-Zope4Py3

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passed ERP5.CodingStyleTest-Zope4Py3-py2

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passed ERP5.UnitTest-Zope4Py3-Py2

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failed ERP5.CodingStyleTest-Zope4Py3

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canceled ERP5.UnitTest-Zope4Py3

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failed ERP5.UnitTest-Zope4Py3-Py2

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failed ERP5.UnitTest-Zope4Py3-Py2

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failed ERP5.UnitTest-Zope4Py3-Py2

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failed ERP5.UnitTest-Zope4Py3-Py2

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