Avoid leaking file handles in PythonPackage

[Flamefire]

Use read_file/write_file to avoid leaking file handles due to the missing close after open. This also improves error reporting (point to read or write)

[Flamefire]

Test report by @Flamefire

Overview of tested easyconfigs (in order)

• SUCCESS Python-3.10.4-GCCcore-11.3.0.eb

Build succeeded for 1 out of 1 (1 easyconfigs in total)
julia.hpc.tu-dresden.de - Linux Rocky Linux 8.7 (Green Obsidian), x86_64, Intel(R) Xeon(R) Platinum 8276M CPU @ 2.20GHz (cascadelake), Python 3.8.13
See https://gist.github.com/Flamefire/9582c830d4e566d7acfa433abd1f4c44 for a full test report.

[boegel]

Test report by @boegel
"Failed to process easyconfig /arcanine/scratch/gent/vo/000/gvo00002/vsc40023/easybuild/easybuild-easyconfigs/easybuild/easyconfigs/m/matplotlib/matplotlib-3.9.2-gfbf-2024a.eb: Failed to obtain class for PythonBundle easyblock (not available?): cannot import name 'run_pip_check' from 'easybuild.easyblocks.generic.pythonpackage' (/tmp/eb-jlg7dvow/included-easyblocks-dyrr5dcm/easybuild/easyblocks/generic/pythonpackage.py)"
Failed during parsing of the easyconfigs, so no ecs were built (2 easyconfigs in total)
node3539.doduo.os - Linux RHEL 9.4, x86_64, AMD EPYC 7552 48-Core Processor (zen2), Python 3.9.18
See https://gist.github.com/boegel/14a2818bc4f35b35e25fe75f4604961d for a full test report.

[boegel]

Test report by @boegel
"Failed to process easyconfig /arcanine/scratch/gent/vo/000/gvo00002/vsc40023/easybuild/easybuild-easyconfigs/easybuild/easyconfigs/m/matplotlib/matplotlib-3.9.2-gfbf-2024a.eb: Failed to obtain class for PythonBundle easyblock (not available?): cannot import name 'run_pip_check' from 'easybuild.easyblocks.generic.pythonpackage' (/tmp/eb-hlgnamx6/included-easyblocks-ududp9pe/easybuild/easyblocks/generic/pythonpackage.py)"
Failed during parsing of the easyconfigs, so no ecs were built (2 easyconfigs in total)
node3539.doduo.os - Linux RHEL 9.4, x86_64, AMD EPYC 7552 48-Core Processor (zen2), Python 3.9.18
See https://gist.github.com/boegel/b46f361a66a3f656c417cde7ca3c5d33 for a full test report.

[boegel]

lgtm

[boegel]

Test report by @boegel

Overview of tested easyconfigs (in order)

• SUCCESS tqdm-4.66.5-GCCcore-13.3.0.eb

Build succeeded for 1 out of 1 (1 easyconfigs in total)
node3539.doduo.os - Linux RHEL 9.4, x86_64, AMD EPYC 7552 48-Core Processor (zen2), Python 3.9.18
See https://gist.github.com/boegel/bfd9c30af030c017f2c0d4337dce3519 for a full test report.