fix(libiconv): only put the static lib on the windows link line

- static-libs@windows listed both libiconv.lib (the dll import lib) and
  libiconv_a.lib; the import lib came first, so php.exe ended up
  importing libiconv.dll and the cli smoke test died with
  STATUS_DLL_NOT_FOUND on machines without it

config/pkg/lib/libiconv-win.yml

@@ -9,5 +9,4 @@ libiconv-win:
       license-files: [source/COPYING]
       license: GPL-3.0-or-later
   static-libs@windows:
-    - libiconv.lib
     - libiconv_a.lib