formula_installer: check for recommended/optional.

build.without? seemingly always returns true for requirements that are
neither recommended nor optional so check these before deciding not to
install a default formula.

Closes #31511.
libav: remove unnecessary configure options
libav: enable VDA code
libav: update 10.3 bottle.

Closes #31490.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
mono: Don't clean mono's runtime directories.

xbuild requires the various .exe files in the runtime directories to
be executable.
mono: update 3.4.0_1 bottle.