fix: remove dead add_typst_font_path Lua API (#13521)

The TypeScript-side handler for "typst-font-path" dependencies was
removed in 7bac8f0 when Typst font handling moved from Lua to
TypeScript, but the Lua API declaration was missed. Remove this
dead code.

Author: gordonwoodhull

src/resources/pandoc/datadir/init.lua

@@ -914,11 +914,6 @@ quarto = {
       writeToDependencyFile(dependency("usepackage", {package = package, options = options }))
     end,
 
-    -- could be add_metadata(namespace, {stuff})
-    add_typst_font_path = function(path)
-      writeToDependencyFile(dependency("typst-font-path", {path = path}))
-    end,
-
     add_format_resource = function(path)
       writeToDependencyFile(dependency("format-resources", { file = resolvePathExt(path)}))
     end,