gpl3_free_deltas: Update document to reflect latest state

The licensing issues and replacement for coreutils-gplv2 are covered in a specific document, so drop the mention in gpl3 free delta to avoid confusions.

Update gpl3_free_deltas after applying the strategies described on it for several packages, such as cpio, diffutils, grep, gzip, sed and tar.

Since the issue is still present on releases earlier than v2023dev0 move the comments to a new section.

https://phabricator.apertis.org/T8146

Signed-off-by: Walter Lozano walter.lozano@collabora.com