audit: Supress pre-release audits for known pre-release formulae

- This safelists one formula that has only ever shipped pre-releases,
  from before we had the GitHub pre-release audit. So it won't fail CI
  and cause maintainers more work to determine if it's always been that
  way, or if it's new. Then, we don't have to keep comments at the top
  of files to say so for the next contributors.
- We should check this list from time to time to make sure that the
  formulae here have graduated to actual releases and we can remove
  them.

Library/Homebrew/dev-cmd/audit.rb

@@ -597,6 +597,8 @@ module Homebrew
       "libepoxy"            => "1.5",
     }.freeze
 
+    GITHUB_PRERELEASE_ALLOWLIST = %w[cake].freeze
+
     # version_prefix = stable_version_string.sub(/\d+$/, "")
     # version_prefix = stable_version_string.split(".")[0..1].join(".")
 
@@ -705,8 +707,11 @@ module Homebrew
 
         begin
           if @online && (release = GitHub.open_api("#{GitHub::API_URL}/repos/#{owner}/#{repo}/releases/tags/#{tag}"))
-            problem "#{tag} is a GitHub prerelease" if release["prerelease"]
-            problem "#{tag} is a GitHub draft" if release["draft"]
+            if release["prerelease"] && !GITHUB_PRERELEASE_ALLOWLIST.include?(formula.name)
+              problem "#{tag} is a GitHub prerelease"
+            elsif release["draft"]
+              problem "#{tag} is a GitHub draft"
+            end
           end
         rescue GitHub::HTTPNotFoundError
           # No-op if we can't find the release.