stack/slapos.cfg: Change pkgutil-resolve-name version to whl

pkgutil-resolve-name=1.3.10 requires flit_core as build backend.

This is used by component/slapos.
5 jobs for dev/buildout-3-prepare-for-mr in 0 seconds
Status Job ID Name Coverage
  External
failed ERP5.UnitTest-Master-Buildout3

03:51:02

passed SlapOS.Buildout.UnitTest-Master.Python3-buildout3

00:11:57

passed SlapOS.Buildout.UnitTest-Master.Python3-buildout3

00:17:02

passed SlapOS.Buildout.UnitTest-Master.Python3-buildout3

00:15:33

passed SlapOS.Buildout.UnitTest-Master.Python3-buildout3

00:30:19