CI on Windows: Disable ffmpeg download, the link is broken (#2729)
CI on Windows: Disable ffmpeg download, the link is broken (#2729)

The web site where we used to download pre-built ffmpeg binaries
seems to have disappeared.

Signed-off-by: Larry Gritz <f0a1ce6f80112d72f7276457fd261d671b827567@larrygritz.com>
lgritz/oiio,OpenImageIO/oiio,lgritz/oiio,lgritz/oiio,OpenImageIO/oiio,OpenImageIO/oiio,OpenImageIO/oiio,lgritz/oiio