[stable-3.8] no longer override the pixman default version

[backportbot-nextcloud]

backport of #5630

[nextcloud-desktop-bot]

AppImage file: nextcloud-PR-5632-abc92f5e1f9777e674f97838a1718ee1d793a044-x86_64.AppImage

To test this change/fix you can simply download above AppImage file and test it.

Please make sure to quit your existing Nextcloud app and backup your data.

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
No Duplication information

[codecov]

Codecov Report

Merging #5632 (abc92f5) into stable-3.8 (5d0a54b) will decrease coverage by 0.01%.
The diff coverage is 39.53%.

Additional details and impacted files

@@              Coverage Diff               @@
##           stable-3.8    #5632      +/-   ##
==============================================
- Coverage       59.27%   59.27%   -0.01%     
==============================================
  Files             143      143              
  Lines           18443    18455      +12     
==============================================
+ Hits            10932    10939       +7     
- Misses           7511     7516       +5     

Impacted Files	Coverage Δ
src/libsync/logger.h	61.53% <ø> (ø)
src/libsync/logger.cpp	28.57% <35.00%> (+0.66%)	⬆️
src/common/syncjournaldb.cpp	78.72% <100.00%> (+0.02%)	⬆️

... and 3 files with indirect coverage changes