(geography/R-spatstat.core) Removed

In https://cran.r-project.org/web/packages/spatstat/NEWS
        CHANGES IN spatstat VERSION 3.0-1

SIGNIFICANT USER-VISIBLE CHANGES

    o Package structure
    The package 'spatstat.core' has been split into two packages called
    'spatstat.explore' (for exploratory data analysis)
    and 'spatstat.model' (for modelling and formal inference).

    o Package dependence
    'spatstat' now depends on the new packages 'spatstat.explore'
    and 'spatstat.model' which have replaced the old package 'spatstat.core'.

(mef)