[No JIRA] Upgrade to Xcode 11.7

[k0nserv]

• Check this if you have read and followed the contributing guidelines

Remember to include the following changes:

• UNRELEASED.md
• README.md
• Tests
• Screenshotting code
• Adding a component? Remember to expose it in the main Backpack.h header file
• Docs (either update backpack-docs now, or create a follow up ticket)

If you are curious about how we review, please read through the code review guidelines

[georgegillams]

If you can get CI to work then all good. You'll need to update snapshots too as they'll probably change ever so slightly between versions.

[k0nserv]

If you can get CI to work then all good. You'll need to update snapshots too as they'll probably change ever so slightly between versions.

Actually seem to be fine locally