Use latest version of SDoc

* Backport of https://github.com/rails/rails/pull/37788 to 6.0-stable
* https://github.com/guard/listen/releases/tag/v3.2.0
* https://github.com/guard/listen/issues/465
* `listen` removed the unmaintained `ruby_dep` dependency, which
  incorrectly shows warnings when running on TruffleRuby.

Rack updated the RFC they're adhering to when parsing cookies, now no
longer including commas.

There's still an open question as mentioned in:
https://github.com/rails/rails/issues/38420

However, the resilience test is no longer as well needed as it once was
and we can move forward separately. If not, this is easily revertible.

https://bugs.ruby-lang.org/issues/16485
https://github.com/ruby/ruby/pull/2832

https://github.com/rack/rack/compare/2.1.0...2.1.1

rack 2.1.0 changed expires date format from rfc2822 to httpdate

https://github.com/seattlerb/minitest/commit/5802aa08280a3609b684e0ebef95dabfbd3ec9ff
https://github.com/seattlerb/minitest/pull/809#discussion_r332399750

To support both 5.13.0 and 5.14.0, use `#initialize` instead.

Distinguish missing controller exceptions from unrelated NameError

The `ActionDispatch::Session::MemcacheStore` is still vulnerable
given it requires the gem dalli to be updated as well.

CVE-2019-16782

Eager load translations during initialization

Fix Railties test suite for Sprockets 4.0

Address to the warning "DEPRECATED: global use of assertion methods"

Fix Active Job Sidekiq integration tests

Rails HTML sanitizer update changes to Gemfile lock on bundle install.

Rails now requires 1.2.0 because it relies on the safe_list_sanitizer
API exclusively.

Also raise `sanitizer_vendor` API from the dead for
rails-deprecated_sanitizer.

Fixes https://github.com/rails/rails-deprecated_sanitizer/pull/6

The PR #36860 changed ActionView's required version of
rails-html-sanitizer, but I missed that we needed to run
bundle, otherwise we end up with changes every time.

Fix Browser#preload for older Selenium

Unlock `selenium-webdriver` gem version

This version makes eager loading and autoloading consistent,
as documented in the upgrading guide.