Deprecation warning with Rack >= 3.0.0 - Rack::File is deprecated and will be removed in Rack 3.1

[mmcnickle-float]

Rack::File will be deprecated in Rack 3.1 (rack/rack#1811). There's been a compatibility layer in place that renames Rack::File to Rack::Files to help the transition since Rack 2.1.0 (https://github.com/rack/rack/blob/main/CHANGELOG.md#210---2020-01-10)

At the minute, the Gemspec gives the compatibility of Rack of >= 1.2.0

I guess there are two approaches to how to resolve this:

1. Change the minimum compatible Rack version to >= 2.1.0 and change the call at https://github.com/MiniProfiler/rack-mini-profiler/blob/master/lib/mini_profiler/actions.rb#L58 to use Rack::Files instead.
2. Keep the minimum compatible Rack version at >= 1.2.0 and write a compatibility check/layer in this gem instead.

I'm not sure which approach the project maintainer prefers?