otto: delete (#17323)
otto: delete (#17323)

- This was deleted upstream (in 2018) in
  https://github.com/Homebrew/homebrew-core/pull/22567 as it's [no longer
  maintained by
  HashiCorp](https://www.hashicorp.com/blog/decommissioning-otto/).
Linuxbrew/homebrew-core,LinuxbrewTestBot/homebrew-core,Linuxbrew/homebrew-core,maxim-belkin/homebrew-core,LinuxbrewTestBot/homebrew-core,rwhogg/homebrew-core,rwhogg/homebrew-core,maxim-belkin/homebrew-core