Closes #19165

### Summary of the issue:

MathPlayer is no longer maintained and is not 64-bit compatible.

### Description of user facing changes:

MathPlayer is no longer supported by NVDA.

### Description of developer facing changes:

MathPlayer code has been removed.

### Description of development approach:

* Deleted the `mathPres.mathPlayer` module
* Removed `mathPlayer_sconscript` and its callers from the build
system
* Fixed a few comments and strings that mentioned MathPlayer
* Removed MathPlayer from miscDeps nvaccess/nvda-misc-deps#48

### Testing strategy:

Rebuilt NVDA and ensured that it still works and MathCAT continues to
function.

### Known issues with pull request:

None