Remove combinatorial optimisation class from qibo repo

[shangtai]

Since qiboopt 0.1.0 has been released, as discussed in #1777, we will remove combinatorial optimisation classes from the main repo.

We have removed

• Traveling Salesman Problem, TSP classes.
• Minimum Vertex Cover, MVC example.
• Quadratic Assignment Programming, QAP example.

Checklist:

• Reviewers confirm new code works as expected.
• Tests are passing.
• Coverage does not decrease.
• Documentation is updated.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.51%. Comparing base (91fb509) to head (9847f55).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1805      +/-   ##
==========================================
- Coverage   99.51%   99.51%   -0.01%     
==========================================
  Files          79       78       -1     
  Lines       13274    13229      -45     
==========================================
- Hits        13210    13165      -45     
  Misses         64       64              

Flag	Coverage Δ
unittests	99.51% <100.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[scarrazza]

@shangtai thanks, please update the sphinx docs too:

qibo/doc/source/api-reference/qibo.rst

Line 177 in 4815b7a

Travelling Salesman Problem

[renatomello]

Are the examples being moved to qiboopt or just removed from here?

[jf-kong]

Thanks @shangtai. Some additional links that should be removed:

1. Examples index links

   • examples/README.md still links to qap/README.md and mvc/README.md

2. Docs toctree entries

   • doc/source/code-examples/applications.rst and doc/source/code-examples/applications-by-topic.rst still include:
     • tutorials/qap/README.md
     • tutorials/mvc/README.md

3. Tutorial pages referencing removed paths

   • doc/source/code-examples/tutorials/qap/README.md and doc/source/code-examples/tutorials/mvc/README.md still point to:
     • https://github.com/qiboteam/qibo/tree/master/examples/qap
     • https://github.com/qiboteam/qibo/tree/master/examples/mvc

[shangtai]

Are the examples being moved to qiboopt or just removed from here?

@renatomello Currently, just remove.

I intend to make them into Classes in qiboopt.