[3.14] GH-141808: Do not generate the jit stencils twice in case of PGO builds on Windows. (GH-142043) (#142100)

GH-141808: Do not generate the jit stencils twice in case of PGO builds on Windows. (GH-142043)

* do not build the jit stencils twice in case of PGO builds on Windows

* blurb it
(cherry picked from commit f2ca1581cab2da45880198af1c924dd40ec8a10b)

Co-authored-by: Chris Eibl <138194463+chris-eibl@users.noreply.github.com>