Update activesupport to 6.1.3.1

What does this MR do?

Updates activesupport from 6.0.3.4 to 6.1.3.1 to address two security vuls CVE-2021-22880 and CVE-2021-22881 fixed in 6.0.3.5 or 6.1.3.1.

activesupport gem was introduced indirectly in !4703 (merged) when rubocop-rails was introduced.

Related issues

n/a

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion

Required

• Merge Request Title, and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com
• Pipeline is green on dev.gitlab.org if the change is touching anything besides documentation or internal cookbooks
• trigger-package has a green pipeline running against latest commit

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Tests added
• Integration tests added to GitLab QA
• Equivalent MR/issue for the GitLab Chart opened