deleted unused param "session" from process_split

[smichr]

References to other Issues or PRs

closes #16594

Brief description of what is fixed or changed

Other comments

Release Notes

• core
  • removed unused parameter from process_split function

[sympy-bot]

✅

Hi, I am the SymPy bot (v145). I'm here to help you write a release notes entry. Please read the guide on how to write release notes.

Your release notes are in good order.

Here is what the release notes will look like:

• core
  • removed unused parameter from process_split function (#16614 by @smellslikekeenspirit and @smichr)

This will be added to https://github.com/sympy/sympy/wiki/Release-Notes-for-1.5.

Note: This comment will be updated with the latest check if you edit the pull request. You need to reload the page to see it.

Click here to see the pull request description that was parsed.

<!-- Your title above should be a short description of what
was changed. Do not include the issue number in the title. -->

#### References to other Issues or PRs
<!-- If this pull request fixes an issue, write "Fixes #NNNN" in that exact
format, e.g. "Fixes #1234". See
https://github.com/blog/1506-closing-issues-via-pull-requests . Please also
write a comment on that issue linking back to this pull request once it is
open. -->
closes #16594

#### Brief description of what is fixed or changed


#### Other comments


#### Release Notes

<!-- Write the release notes for this release below. See
https://github.com/sympy/sympy/wiki/Writing-Release-Notes for more information
on how to write release notes. The bot will check your release notes
automatically to see if they are formatted correctly. -->

<!-- BEGIN RELEASE NOTES -->
* core
    * removed unused parameter from process_split function
<!-- END RELEASE NOTES -->

Update

The release notes on the wiki have been updated.

[codecov]

Codecov Report

Merging #16614 into master will increase coverage by 0.012%.
The diff coverage is n/a.

@@              Coverage Diff              @@
##            master    #16614       +/-   ##
=============================================
+ Coverage   73.739%   73.752%   +0.012%     
=============================================
  Files          619       619               
  Lines       158731    158728        -3     
  Branches     37208     37206        -2     
=============================================
+ Hits        117048    117066       +18     
+ Misses       36268     36245       -23     
- Partials      5415      5417        +2