feat(plugin download): add application/x-zip-compressed for header Accept

[jmkerloch]

Some server might not consider plugin .zip as application/zip but application/x-zip-compressed.

In this case, the server doesn't return the plugin .zip but an error page.

In this PR we add application/x-zip-compressed to the header Accept to fix this issue.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 70.35%. Comparing base (3c2c7ca) to head (49fbc32).
Report is 4 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #587   +/-   ##
=======================================
  Coverage   70.35%   70.35%           
=======================================
  Files          47       47           
  Lines        3188     3188           
  Branches      558      558           
=======================================
  Hits         2243     2243           
  Misses        747      747           
  Partials      198      198           

Flag	Coverage Δ
unittests	69.79% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...deployment_toolbelt/jobs/job_plugins_downloader.py	50.37% <ø> (ø)

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud