loongson/pypi/: pyqt5 versions

Because this project isn't in the mirror_whitelist, no releases from root/pypi are included.

Latest version on stage is: 5.15.10

Python bindings for the Qt cross platform application toolkit

Index Version Documentation
loongson/pypi 5.15.10
loongson/pypi 5.15.7
loongson/pypi 5.15.4