support nokogiri for arm

[mfenner]

Purpose

Require nokogiri version that supports Apple Silicon (1.13.1)

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Reviewer, please remember our guidelines:

• Be humble in the language and feedback you give, ask don't tell.
• Consider using positive language as opposed to neutral when offering feedback. This is to avoid the negative bias that can occur with neutral language appearing negative.
• Offer suggestions on how to improve code e.g. simplification or expanding clarity.
• Ensure you give reasons for the changes you are proposing.

[richardhallett]

This is in theory fine but my concern is the requirements on Ruby 2.7, but I think any other upgrades for other software needs to hit 2.7 at some point so with that in mind this can go ahead.

[orangewolf]

In my opinion 2.7 is table stakes now and it would be great to get this in.