Automatic update for pungi-4.2.3-2.fc33.

Changelog

* Thu Jun 11 2020 Lubomír Sedlář <lsedlar@redhat.com> - 4.2.3-2
- Stop building PDF documentation
* Thu Jun 11 2020 Lubomír Sedlář <lsedlar@redhat.com> - 4.2.3-1
- Move test for unsigned packages with pkgset_koji_scratch_tasks to PkgsetPhase
  class. (jkaluza)
- Allow building compose with scratch builds defined by
  `pkgset_koji_scratch_tasks`. (jkaluza)
- createrepo: Allow making productid glob stricter (lsedlar)
- docs: Remove outdated note (lsedlar)
- createrepo: Add extra modulemd files to the repo (lsedlar)
- pkgset: handle exception when using dogpile cache (hlin)
- notification: Add compose_path into the messages (hlin)
- gather: handle mirrorlist in kickstart (frederic.pierret)
- Allow only creating unified ISO for specified arch (hlin)
- docs: update doc for gather_lookaside_repos option (hlin)
- Include the output of getisoimage in the error message (hlin)
- tests: Patch time in CTS related tests (lsedlar)
- Allow using Pungi Koji plugin for ostree phases. (jkaluza)
- Allow getting the compose id from CTS (Compose Tracking Service). (jkaluza)
- Fix flake8 issues (lsedlar)
- Optimize the _link_file function to not call os.stat redundantly. This will
  eliminate 2 calls to os.stat per one invocation of the _link_file function.
  Assuming during the compose build 50000 files are linked, this change will
  eliminate 100000 redundant calls to os.stat. (bkhomuts)
- doc: explain sigkey behavior (kdreyer)
- doc: explain tradeoffs with pkgset_allow_reuse (kdreyer)
- doc: fix grammar for pkgset_allow_reuse setting (kdreyer)
- Support --skip-branding option in lorax (hlin)
- docs: Embed phases.svg directly (hlin)
- Execute image_checksum phase right after the dependent phases (hlin)