Unify `Lzma` and `Xz`.

Library/Homebrew/unpack_strategy/lzma.rb

@@ -19,6 +19,12 @@ module UnpackStrategy
       path.magic_number.match?(/\A\]\000\000\200\000/n)
     end
 
+    def dependencies
+      @dependencies ||= [Formula["xz"]]
+    end
+
+    private
+
     sig { override.params(unpack_dir: Pathname, basename: Pathname, verbose: T::Boolean).returns(T.untyped) }
     def extract_to_dir(unpack_dir, basename:, verbose:)
       FileUtils.cp path, unpack_dir/basename, preserve: true
@@ -28,9 +34,5 @@ module UnpackStrategy
                       env:     { "PATH" => PATH.new(Formula["xz"].opt_bin, ENV["PATH"]) },
                       verbose: verbose
     end
-
-    def dependencies
-      @dependencies ||= [Formula["xz"]]
-    end
   end
 end