TL: handling duplicates in points for the LagrangeApproximation class

[tlunet]

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Description

In case duplicates points are given to the LagrangeApproximation class, and algorithm handle the generation of the interpolation, integration and derivation matrix by using specifically some values and ignoring others. Two algorithms are implemented here :

• USE_LEFT (default) : use the first provided fonction value on a duplicated point
• USE_RIGHT : use the last provided function value on a duplicated point

In addition, a base tutorial on the qmat.lagrange module has been added.

⚠️ This PR also deprecates python 3.8 tests, add python 3.13 tests and imposes numpy>=2

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (0c561fa) to head (f749af1).

Additional details and impacted files

@@            Coverage Diff            @@
##              main       #16   +/-   ##
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  Coverage   100.00%   100.00%           
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  Files           15        15           
  Lines         1369      1408   +39     
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+ Hits          1369      1408   +39     

Flag	Coverage Δ
smart-tests	100.00% <100.00%> (ø)

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