[ci] PETSc pkg-config fixes

See merge request ogs/ogs!4844

[py] Import OpenGeoSys module properly

See merge request !4843

mtest / tfel python bindings are not available on the test machines
and are therefore skipped.

Affects ModCamClay_TestIsotrop.ipynb.

Needs to be imported with:

try:
    import ogs.callbacks as OpenGeoSys
except ModuleNotFoundError:
    import OpenGeoSys

`ogs.callbacks` is needed when imported via pip installed package.
`import OpenGeoSys` else.

Tests thermo poro elasticity relax tolerance

See merge request !4841

[nb] Make tfel available

See merge request !4842

[cmake] Simplify PETSc finding

See merge request !4839

[cmake] Use VTK 9.3 on gcc 13.2.

See merge request ogs/ogs!4840

Fixes compile errors in VTK.

This is now recommended. See

https://lists.mcs.anl.gov/pipermail/petsc-users/2019-December/039937.html

FindPETSc.cmake was used.

[cmake] Refactor netCDF library finding

See merge request ogs/ogs!4814

Code cleanup: Move code from NumLib to MathLib

See merge request ogs/ogs!4833

BHE 1P Benchmark fixes

See merge request ogs/ogs!4834

Also remove scaling of the right error axis
to see the full scale.

Fixing the xpath and the end time with time increments

add the numerical stabilization type "FCT" and apply it to ComponentTransport process

See merge request ogs/ogs!4825