sage.matrix: Modularization fixes after #33159

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We add `# optional - sage.symbolic` doctest tags
after #33159.

Component: **refactoring**

Author: **Matthias Koeppe**

Branch/Commit: **[`2f8a489`](https://github.com/sagemath/sagetrac-mirror/commit/2f8a4890a1ca670d8282b35204c0e49ee4383e54)**

Reviewer: **Michael Orlitzky**

_Issue created by migration from https://trac.sagemath.org/ticket/33392_

