Python files installed in /usr/local/lib break reproducibility

Since #14680 (closed) and the installation of the Tails pythonlib in the ISO, it’s not possible to reproduce the ISO anymore.

See https://nightly.tails.boum.org/reproducibly_build_Tails_ISO_stable/builds/193/archive/build-artifacts/diffoscope.html for more details.

Feature Branch: bugfix/15400-python-lib-breaks-reproducibility

Related issues

• Related to #15421 (closed)
• Blocks #15417 (closed)

Original created by @bertagaz on 15400 (Redmine)