Update metadata cache for upstream's eclass changes
[plac] Drop Python 2.5 support

Package-Manager: portage-2.2.1
Manifest-Sign-Key: C0174749
[multiprocessing] No longer required

The removal of Python 2.5 upstream has removed the need for this.
[QA] Remove errorneous ChangeLog entry in python-importlib
Manual update of removal texts
[jsonpipe] Drop Python 2.5 support

Package-Manager: portage-2.2.1
Manifest-Sign-Key: C0174749
[html2rest] Drop Python 2.5 support

Package-Manager: portage-2.2.1
Manifest-Sign-Key: C0174749