Revert "Recompile when config.yml changes"

* This reverts commit ffe8f7a.
* No longer necessary as the Makefile depends on all *.c and *.h.

Author: eregon

ext/prism/depend

@@ -42,8 +42,6 @@ Gem::Specification.new do |spec|
     "docs/serialization.md",
     "docs/testing.md",
     "ext/prism/api_node.c",
-    "ext/prism/depend",
-    "ext/prism/extconf.rb",
     "ext/prism/extension.c",
     "ext/prism/extension.h",
     "include/prism.h",