Backport PR #47946: REGR: fix error caused by deprecation warning in pd.merge when joining two Series
#47946 

cc @simonjayhawkins Added the pr number > cc @simonjayhawkins Added the issue number

we need to do the issue number as a sperate PR against main (and either backport or sync directly with 1.4.x) so that the release notes history on the future stable docs are also correct Yep, already prepared the pr