MatrixSpace: Use Matrix_symbolic_dense for all symbolic rings, not just SR

[mkoeppe]

... in analogy to the change made in #31999 for free modules.

We may also want to add Matrix_callable_symbolic_dense (in analogy to Vector_callable_symbolic_dense)

Depends on #16761

CC: @egourgoulhon @mjungmath @tscrim

Component: linear algebra

Issue created by migration from https://trac.sagemath.org/ticket/31988

[mkoeppe]

Description changed:

--- 
+++ 
@@ -1,4 +1,4 @@
-... in analogy to the change made in #31982 for free modules.
+... in analogy to the change made in #31999 for free modules.
 
 We may also want to add `Matrix_callable_symbolic_dense` (in analogy to `Vector_callable_symbolic_dense`)
 

[mkoeppe]

Dependencies: #16761