fixing some E502 in tensor, dynamics, modules, plot, numerical

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E502 the backslash is redundant between brackets


Depends on #34839

Component: **refactoring**

Author: **Frédéric Chapoton**

Branch/Commit: **[`4bc07ec`](https://github.com/sagemath/sagetrac-mirror/commit/4bc07ec05f42f56681d89a9e31610270d3b0aa96)**

Reviewer: **Matthias Koeppe**

_Issue created by migration from https://trac.sagemath.org/ticket/34891_

