Please remove Depends: pkg-config from php8.6-dev

pkg-config has been a transitional package depending on pkgconf since Debian 12.

While some -dev packages do have Depends: pkgconf, most don't. I think
that it is probably unnecessary for -dev packages to have that
dependency. Many packages will need to have pkgconf in their
Build-Depends instead.

Thank you,
Jeremy Bícha