Implement delay_on_commit to celery tasks

[harriebird]

Proposed changes

Implement delay_on_commit to celery tasks.
This solves issue #10049.

Checklist

• Lint and unit tests pass locally with my changes.
• I have added tests that prove my fix is effective or that my feature works.
• I have added documentation to describe my feature.
• I have squashed my commits into logic units.
• I have described the changes in the commit messages.

Other information

[codecov]

Codecov Report

Attention: Patch coverage is 71.42857% with 4 lines in your changes are missing coverage. Please review.

Project coverage is 90.62%. Comparing base (6aee586) to head (49410af).
Report is 1733 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #11624      +/-   ##
==========================================
- Coverage   90.82%   90.62%   -0.20%     
==========================================
  Files         554      570      +16     
  Lines       57306    58615    +1309     
  Branches     9122     9363     +241     
==========================================
+ Hits        52046    53122    +1076     
- Misses       3640     3809     +169     
- Partials     1620     1684      +64     

Files	Coverage Δ
weblate/accounts/models.py	86.89% <100.00%> (-0.28%)	⬇️
weblate/addons/autotranslate.py	84.61% <100.00%> (+6.83%)	⬆️
weblate/trans/models/change.py	82.40% <100.00%> (+3.39%)	⬆️
weblate/trans/models/project.py	91.64% <100.00%> (-1.07%)	⬇️
weblate/trans/models/unit.py	86.15% <100.00%> (-0.15%)	⬇️
weblate/trans/models/component.py	79.38% <50.00%> (-0.57%)	⬇️
weblate/utils/stats.py	93.41% <0.00%> (-0.23%)	⬇️

... and 239 files with indirect coverage changes

[nijel]

Merged, thanks for your contribution!