Add optional package cvxpy, update cylp, add CVXPY MIP backend

[mkoeppe]

📚 Description

Fixes #34251

📝 Checklist

• I have made sure that the title is self-explanatory and the description concisely explains the PR.
• I have linked an issue or discussion.
• I have created tests covering the changes.
• I have updated the documentation accordingly.

⌛ Dependencies

[codecov-commenter]

Codecov Report

Patch coverage has no change and project coverage change: -0.01 ⚠️

Comparison is base (c00e6c2) 88.62% compared to head (9f75342) 88.61%.

❗ Current head 9f75342 differs from pull request most recent head 0324f53. Consider uploading reports for the commit 0324f53 to get more accurate results

Additional details and impacted files

@@             Coverage Diff             @@
##           develop   #35120      +/-   ##
===========================================
- Coverage    88.62%   88.61%   -0.01%     
===========================================
  Files         2148     2148              
  Lines       398855   398855              
===========================================
- Hits        353480   353452      -28     
- Misses       45375    45403      +28     

see 25 files with indirect coverage changes

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[dimpase]

are there any tests to see this working?

[mkoeppe]

In addition to the tests in cvxpy_backend, you can do echo "default_mip_solver('cvxpy')" > ~/.sage/init-doctests.sage and run ./sage -t src/sage/{combinat,graphs,numerical}

[dimpase]

lgtm

[mkoeppe]

Thank you!

[vbraun]

Merge conflict

[mkoeppe]

trivial merge, back to positive review

[vbraun]

I though there is now a CI test that builds the PDF docs? Because this ticket doesn't build because of an invisible U+200B:

[sagemath_doc_pdf-none] LaTeX Warning: Hyper reference `six:spkg-six' on page 75 undefined on input lin
[sagemath_doc_pdf-none] e 6824.
[sagemath_doc_pdf-none] 
[sagemath_doc_pdf-none] [75]
[sagemath_doc_pdf-none] 
[sagemath_doc_pdf-none] ! Package inputenc Error: Unicode character ​ (U+200B)
[sagemath_doc_pdf-none] (inputenc)                not set up for use with LaTeX.
[sagemath_doc_pdf-none] 
[sagemath_doc_pdf-none] See the inputenc package documentation for explanation.
[sagemath_doc_pdf-none] Type  H <return>  for immediate help.
[sagemath_doc_pdf-none]  ...                                              
[sagemath_doc_pdf-none]                                                   
[sagemath_doc_pdf-none] l.6897 ​
[sagemath_doc_pdf-none]           https://www.gnu.org/licenses/license\sphinxhyphen{}list.html\#EPL2;
[sagemath_doc_pdf-none] ? 
[sagemath_doc_pdf-none] ! Emergency stop.
[sagemath_doc_pdf-none]  ...                                              
[sagemath_doc_pdf-none]                                                   
[sagemath_doc_pdf-none] l.6897 ​
[sagemath_doc_pdf-none]           https://www.gnu.org/licenses/license\sphinxhyphen{}list.html\#EPL2;
[sagemath_doc_pdf-none] !  ==> Fatal error occurred, no output PDF file produced!

[mkoeppe]

I though there is now a CI test that builds the PDF docs?

That PR #35169 is still waiting for review

[dimpase]

here is the problem:

--- a/build/pkgs/cylp/SPKG.rst
+++ b/build/pkgs/cylp/SPKG.rst
@@ -9,7 +9,11 @@ A Python interface for CLP, CBC, and CGL
 License
 -------

-Eclipse Public License
+Eclipse Public License (EPL) version 2 (without a Secondary Licenses Notice).
+
+Note: This license is incompatible with the GPL according to
+<200b>https://www.gnu.org/licenses/license-list.html#EPL2;
+see also the discussion in :trac:`26511`.
 

[github-actions]

Documentation preview for this PR is ready! 🎉
Built with commit: 0324f53