Remove duplicated PYTHONPATH module entries

[Flamefire]

Those ECs set the PYTHONPATH again which is already done by the used easyblock leading to a slower module/python

Running into #13432 while testing this, hence fixed here

Fixes #13432

[Flamefire]

Test report by @Flamefire
SUCCESS
Build succeeded for 9 out of 9 (9 easyconfigs in total)
taurusi6606.taurus.hrsk.tu-dresden.de - Linux RHEL 7.9, x86_64, Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz (haswell), Python 2.7.5
See https://gist.github.com/2d840b4654b1b42b376970cfcd5f8654 for a full test report.

Note: Tested all I could, excluded intel-2017 ECs from the test due to license issues

[Flamefire]

@boegel Anything required here?

[Flamefire]

Test report by @Flamefire
SUCCESS
Build succeeded for 7 out of 7 (7 easyconfigs in total)
taurusi6403.taurus.hrsk.tu-dresden.de - Linux RHEL 7.9, x86_64, Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz (haswell), Python 2.7.5
See https://gist.github.com/707a7b7b242d937161c72c27abe8d055 for a full test report.

[Flamefire]

Updated/rebased again and verified with grep -E ": 'lib/python[^/]+/site-packages'" $(grep --files-with-matches -Er "\\beasyblock = '(ConfigureMakePythonPackage|PythonBundle)'") that all are updated

[boegel]

@Flamefire All these easyconfigs have already been archived in the 5.0.x branch because they're using deprecated or unsupported toolchains, see also https://docs.easybuild.io/policies/toolchains, so I'm not sure it's worth pursuing this (sorry).

Can we enhance the easyconfigs test suite so these duplicated PYTHONPATH entries can be avoided going forward?

[Flamefire]

@Flamefire All these easyconfigs have already been archived in the 5.0.x branch because they're using deprecated or unsupported toolchains, see also https://docs.easybuild.io/policies/toolchains, so I'm not sure it's worth pursuing this (sorry).

Hm, ok

Can we enhance the easyconfigs test suite so these duplicated PYTHONPATH entries can be avoided going forward?

Maybe: #19061

[Flamefire]

Can this be merged? Fixed conflicts again

[Flamefire]

Closing for #20960