[2.0.0] Drop Python 2 support

[Andersson007]

Drop Python 2 support

• Announce the drop now Announce Python 2 support drop; add related entries to ignore-2.19.txt #215
• Right before release 2.0.0 and only after the last 1.* release is done,
  • do a similar PR fix: Resolve pylint issues on the latest CI pipeline community.libvirt#217
  • remove lines from ignore txt added in Announce Python 2 support drop; add related entries to ignore-2.19.txt #215
  • add a changelog fragment similar to what was added in Announce Python 2 support drop; add related entries to ignore-2.19.txt #215 confirming the drop