Update ruby to 2.7.5

Ruby 2.7.4 has security issues fixed in 2.7.5

• CVE-2021-41817
• CVE-2021-41816
• CVE-2021-41819

Link to most recent ruby update:

• gitlab#335890 (closed)

Required MRs

• gitlab-rails: gitlab!76071 (merged)
• gitaly-ruby: gitaly!4171 (merged)
• build images: gitlab-build-images!462 (merged)
• CNG: https://gitlab.com/gitlab-org/security/charts/components/images/-/merge_requests/6
• omnibus: https://gitlab.com/gitlab-org/security/omnibus-gitlab/-/merge_requests/167
• gitlab chart:
• GDK: gitlab-development-kit!2301 (merged) & gitlab-development-kit!2307 (merged)
• GCK:
• labkit:
• gitlab-exporter:
• gitlab-experiment:
• gitlab-docs: gitlab-docs!2299 (merged)