www/rubygem-rack22: update to 2.2.6.2

Required for gitlab-ce 15.8
Fixes security related issues:
CVE-2022-44570
CVE-2022-44571
CVE-2022-44572

Changelog:
https://github.com/rack/rack/blob/2-2-stable/CHANGELOG.md
(cherry picked from commit 4e049f8e40c47d3e0105859c83ef992faf5cd45d)