Improve reliability of profiles sync with only_missing

[Guts]

No description provided.

[codecov-commenter]

Codecov Report

Merging #228 (f4140e4) into main (e136fea) will decrease coverage by 4.88%.
The diff coverage is 0.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #228      +/-   ##
==========================================
- Coverage   68.37%   63.49%   -4.88%     
==========================================
  Files          33       33              
  Lines        1755     1767      +12     
  Branches      375      381       +6     
==========================================
- Hits         1200     1122      -78     
- Misses        454      546      +92     
+ Partials      101       99       -2     

Impacted Files	Coverage Δ
...loyment_toolbelt/jobs/job_profiles_synchronizer.py	42.27% <0.00%> (-4.58%)	⬇️
qgis_deployment_toolbelt/utils/win32utils.py	17.64% <0.00%> (-50.00%)	⬇️
...loyment_toolbelt/jobs/job_environment_variables.py	65.78% <0.00%> (-21.06%)	⬇️
qgis_deployment_toolbelt/profiles/shortcuts.py	50.00% <0.00%> (-18.75%)	⬇️