fleet-db: boneyard

Upstream is completely dead, formula hasn't been updated to the most recent
release which was available years ago, tried to update and resulting install
doesn't seem to function as expected.

Closes Homebrew/homebrew#49635.

Library/Homebrew/tap_migrations.rb

@@ -59,6 +59,7 @@ TAP_MIGRATIONS = {
   "feh" => "homebrew/x11",
   "ffts" => "homebrew/boneyard",
   "figtoipe" => "homebrew/head-only",
+  "fleet-db" => "homebrew/boneyard",
   "fox" => "homebrew/x11",
   "freeglut" => "homebrew/x11",
   "freerdp" => "homebrew/x11",