(maint) Fix version number
(maint) Fix version number

A previous change switched to using CMake's project macro to declare the
version. There was a mistake in updating the template that makes that
available for `--version` that caused the version not to be printed. Fix
so the version prints correctly.

puppetlabs/pxp-agent,puppetlabs/pxp-agent,puppetlabs/pxp-agent