Test in CI that it's possible to find libQuotient on GNU/Linux using pkg-config

[KitsuneRal]

Should it be in libQuotient or in Quaternion CI though?..

[KitsuneRal]

Just a comment: finding libQuotient via pkg-config is only useful when a non-CMake Linux-based project needs libQuotient - which is a very corner case. That being said, we ship the pkg-config file, hence it should be tested.