allow and build on Rails 7.1

[jrochkind]

No description provided.

[jrochkind]

Odd failures on Rails 7.1, may be test harness, not sure?

eg

  6) browse_everything/_files.html.erb a directory has the select-all checkbox
     Failure/Error: expect(page).to have_selector('input.ev-select-all')
     
     NoMethodError:
       undefined method `css' for "  <table id=\"file

[jrochkind]

use standard Rails assert_select instead of trying to make our own Capybara::Node::Simple

The Capybara::Node::Simple method stopped working in Rails 7.1 for unknown reasons. But it turns out rails own assert_select is available here; while not looking like rspec style, it works, and is good enough, and supported, without figuring out a non-standard fragile solution.

[jrochkind]

Thanks @jeremyf !