Using Ubuntu 21.10 and trying to install php-dev, getting libpcre2-dev : Depends: libpcre2-8-0
we could revert packages from ppa's that are newer as from ubuntu sources with apt pinning.
sudo apt install apt-show-versions
To identify how many packages are involved run
apt-show-versions | fgrep newer
If are not many packages listed you have a good chance to fix brocken depencecies.
community wiki
The right values you can get from the output from
apt-cache policy
Note: Make a backup first and draw an iso so you can make a clean install. apt pinning is the last ditch to set things right It can work but it is not guaranteed