update CE to EE update guide for 9.5

As seen on https://gitlab.com/gitlab-org/gitlab-ce/issues/36157

assigned to @axil

approved this merge request

enabled an automatic merge when the pipeline for 085afbd6 succeeds

added Pick into Stable label

canceled the automatic merge

merged

mentioned in commit a61057f6

Picked into 9-5-stable-ee, will go into 9.5.0 RC2.

removed Pick into Stable label

mentioned in commit bebd0470