Fix typo in CMS 6.2 changelog

[GuySartorelli]

The following change needs to be made to the CMS 6.2 changelog (including the beta changelog):

- Keyboard navigation has been improved for the in the “Files” admin section. The files gallery and table views both now use a roving tabindex.
+ Keyboard navigation has been improved in the “Files” admin section. The files gallery and table views both now use a roving tabindex.

(remove "for the")

PRs

• DOC Fix typo in CMS 6.2.0 changelog #884