The package webkit2gtk is forked for PureOS but packaging hints Vcs-Browser and Vcs-Git points to Debian Salsa where (seemingly) the PureOS release is not maintained.
Please adjust those Vcs-* tags.
While at it, please also update Maintainer field as requested at https://wiki.debian.org/Derivatives/Guidelines#Packages (regardless of not strongly required by our own guidelines at https://tracker.pureos.net/w/development/packaging_overview/)