Version and style sync across standard- repos

[mjankowski]

Context: standardrb/standard#658

As described in linked PR, bump some stuff to get a clean, no warnings local run, add simplecov, etc. This one also includes an actions/checkout bump which removes CI warnings.

No issues found w/ standard 1.41.1 bump here.

As noted in linked PR, this one (sorbet) was the only one with remaining warning/deprecation output, which is like:

warning: `Cop.registry` is deprecated. Use `Registry.global` instead.

These are coming from (and have since been fixed in) rubocop-sorbet. We're on 0.7.0, 0.8.7 is current, they were fixed in 0.8.4.

Presumably whenever this is next version bumped and rules contemplated, that warning will go away.

[maxveldink]

@searls Do we have an appetite to look at the latest Sorbet rules and decide which ones we want to incorporate?

[maxveldink]

@mjankowski Updating the bundler version is what's causing the 2.7 check to fail. We might want to pull that out of this PR, and think about dropping Ruby 2.7 support in a separate PR.

[searls]

@maxveldink happy to defer to you. I haven't used sorbet since we made this gem so feel free to drive things here

[maxveldink]

Will take a stab in the coming days 👍🏻

[mjankowski]

@mjankowski Updating the bundler version is what's causing the 2.7 check to fail. We might want to pull that out of this PR, and think about dropping Ruby 2.7 support in a separate PR.

Ah, I missed that we had not yet dropped 2.7 in this repo. Updated the PR to remove the bundler version lockfile bump, will watch CI on next run.

I assume (based on linked PR discusssion) that we might WANT to drop 2.7? If so, I can do that as followup here.