sage.matrix: Modularization fixes after #33159

[mkoeppe]

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

Component: refactoring

Author: Matthias Koeppe

Branch/Commit: 2f8a489

Reviewer: Michael Orlitzky

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

[mkoeppe]

Branch: u/mkoeppe/sage_matrix__modularization_fixes_after__33159

[mkoeppe]

Commit: 2f8a489

[mkoeppe]

New commits:

b28224b	src/sage/matrix/matrix2.pyx: Add # optional - sage.symbolic
2f8a489	src/sage/matrix/matrix2.pyx: Use sage.rings.abc.SymbolicRing for isinstance testing

[mwageringel]

comment:3

How can I test this? And how do we prevent this from happening again?

[mkoeppe]

comment:4

I noticed it by running #32432 (see test instructions on the ticket description).

[mkoeppe]

comment:5

Replying to @mwageringel:

how do we prevent this from happening again?

When #32432 or #32601 are merged, we can add it to our automated tests.

[slel]

Description changed:

--- 
+++ 
@@ -1 +1,2 @@
-
+We add `# optional - sage.symbolic` doctest tags
+after #33159.

[orlitzky]

Reviewer: Michael Orlitzky

[orlitzky]

comment:7

Well, it can't hurt. Except for that one isinstance() which LGTM.

[mkoeppe]

comment:8

Thanks!

[vbraun]

Changed branch from u/mkoeppe/sage_matrix__modularization_fixes_after__33159 to 2f8a489