v6.5.2

The plain copy of the official LHAPDF release 6.5.2.
i.e.:

• https://gitlab.com/hepcedar/lhapdf/-/tree/lhapdf-6.5.2
• https://lhapdf.hepforge.org/downloads/?f=LHAPDF-6.5.2.tar.gz

This is a tag of the master branch of alisw/LHAPDF, updated today with a proper bump from v6.2.1 to v6.5.2.

• One may anticipate a need to later put in place some ALICE patches for our own compilation within AliGenerators or O².
  In such a case, we will:

1. create a new ALICE-base development branch, named like alice/v6.5.2
2. and stamp from there tags like v6.5.2-alice1.

For today, let's simply give a try with an untouched copy of the official release.