tig: depend on asciidoc and xmlto at build time for head (#23125)

Fixes man install for head

Formula/tig.rb

@@ -13,8 +13,11 @@ class Tig < Formula
 
   head do
     url "https://github.com/jonas/tig.git"
+
+    depends_on "asciidoc" => :build
     depends_on "autoconf" => :build
     depends_on "automake" => :build
+    depends_on "xmlto" => :build
   end
 
   depends_on "readline" => :recommended