Revert "package/pkg-python: invalidate precompiled _sysconfigdata*.pyc"

This causes build failure for the first host python package get built,
because the $(STAGING_DIR)/usr/lib/python* may not yet exist by tht
time, so find will whine and fail.

This was was alrady the case for the existing find call, a few lines
above, but that was ignored as find is a left-hand-side of a pipe, so
its return code was ignored.

Fixes:
    http://autobuild.buildroot.org/results/860a188bd270c59b1fee2f56f31e73689f0e4979/build-end.log



... where we can see the two find error messages, but only the second
one causes the breakage.

This reverts commit 836528f0.

Reported-by: James Hilliard <james.hilliard1@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Herve Codina <herve.codina@bootlin.com>