lang/ruby27: Update to 2.7.6

ReleaseNotes: https://www.ruby-lang.org/en/news/2022/04/12/ruby-2-7-6-released/
PR: 263250
Exp-run by: antoine
Approved by: sunpoet (ruby@)
MFH: 2022Q2
Security: 06ed6a49-bad4-11ec-9cfe-0800270512f4

(cherry picked from commit dc1e57cf9170bfb3f7f29af852dd3e03d5c2db5b)