gnu-units: Fix Python 2 path for units_cur, fixes Homebrew/homebrew#46527

Formula/gnu-units.rb

@@ -28,6 +28,9 @@ class GnuUnits < Formula
   patch :DATA
 
   def install
+    # OS X does not provide a `python2` executable
+    inreplace "units_cur", "#!/usr/bin/python2", "#!/usr/bin/env python"
+
     args = ["--prefix=#{prefix}"]
     args << "--program-prefix=g" if build.without? "default-names"