Log Message:
misc/ruby-ohai: update to 16.0.20

Update ruby-ohai to 16.0.20 for ruby-chef 16.0.287.

16.0.20 (2020-04-28)

* Bump to version 16.0.0 #1420 (tas50)
* Allow chef-config 16 #1422 (tas50)
* Use is_a? to check the class in the DMI plugin #1423 (tas50)
* fix [#1406]: ensure optional_plugins to be array of symbols #1408 (salzig)
* Replace filesystem with filesystem2 on aix/solaris/bsd #1426 (tas50)
* Chefstyle fixes from Rubocop 0.80 #1431 (tas50)
* Minor testing updates #1432 (tas50)
* use bool instead of raise/rescue to detect linux user is exists #1434 (sawanoboly)
* Combine Linux / Windows fips plugins into a single plugin #1437 (tas50)
* Add logic to fetch the latest azure metadata version #1427 (tas50)
* Expose NIC channel params, coalesce params, and driver info... #1439 (matt-c-clark)
* Add a new interrupts plugin for Linux #1440 (davide125)
* Add a new ipc plugin for Linux #1441 (davide125)
* Fix test failure from missing require. #1442 (phiggins)
* Use native Expeditor gem caching & fix code owners #1443 (tas50)
* Cache gem installs in Buildkite on Windows as well #1444 (tas50)
* Make shard plugin more resilient and throw better errors #1446 (jaymzh)
* Fix chefstyle violations. #1449 (phiggins)
* Add a plugin for Windows mimicing the Unix dmi plugin #1445 (phiggins)
* Use correct DMI attribute name for product name #1451 (ramereth)
* Avoid constant warnings when reloading ohai plugins #1456 (tas50)