fix(check-desktop-strings): order, logging, Focal/bullseye compatibility

[cfm]

Status

Ready for review

Description of Changes

• Fixes CI Lint check failing because check-desktop-files always fails in CircleCI. #7007, by enforcing forwards compatibility of Ubuntu Focal's gettext 0.19.8 with Debian bullseye's gettext 0.21, plus cosmetic changes contributed by @zenmonkeykstop.
• Advises on how to get Weblate pull requests with changes in securedrop/desktop to pass CI.

Testing

• CI lint should, indeed, pass for the translations in develop after Translations update from Weblate #6984.

• Optional: Locally confirm the expected behavior for current translations:

  (.venv) user@sd-dev:~/securedrop$ make check-desktop-files
  ███ Checking desktop translation catalogs...
  make[2]: Nothing to be done for 'install_files/ansible-base/roles/tails-config/templates/ssh_config.j2'.
  (.venv) user@sd-dev:~/securedrop$ securedrop/bin-dev-shell^C
  (.venv) user@sd-dev:~/securedrop$ securedrop/bin/dev-shell make -C .. check-desktop-files
  [...]
  make: Entering directory '/home/user/securedrop'
  ███ Checking desktop translation catalogs...
  make[2]: Nothing to be done for 'install_files/ansible-base/roles/tails-config/templates/ssh_config.j2'.
  make: Leaving directory '/home/user/securedrop'

• Optional: Locally confirm the expected behavior on future translations:

  (.venv) user@sd-dev:~/securedrop$ head install_files/ansible-base/roles/tails-config/templates/locale/LINGUAS > install_files/ansible-base/roles/tails-config/templates/locale/LINGUAS 
  (.venv) user@sd-dev:~/securedrop$ make check-desktop-files
  ███ Checking desktop translation catalogs...
  make[2]: Nothing to be done for 'install_files/ansible-base/roles/tails-config/templates/ssh_config.j2'.
  Desktop files are out of date. Please run "make update-desktop-files" and commit the changes.
  make: *** [Makefile:388: check-desktop-files] Error 1
  (.venv) user@sd-dev:~/securedrop$ securedrop/bin/dev-shell make -C .. check-desktop-files
  make: Entering directory '/home/user/securedrop'
  ███ Checking desktop translation catalogs...
  make[2]: Nothing to be done for 'install_files/ansible-base/roles/tails-config/templates/ssh_config.j2'.
  Desktop files are out of date. Please run "make update-desktop-files" and commit the changes.
  make: *** [Makefile:388: check-desktop-files] Error 1
  make: Leaving directory '/home/user/securedrop'

Deployment

Tooling-only; no deployment considerations.

[legoktm]

Test plan checks out, so LGTM. Not merging in case you want to do #7007 (comment) and fold that into this PR. (But if that's separate/merits further discussion, that's fine too IMO).

[cfm]

We've gone back and forth enough already that I might as well include it here. :-) Let me know what you think of 60f8afb.

[legoktm]

Perfect, thanks :) Will merge once CI passes!