It seems that MOLD_MOSTLY_STATIC was required before to avoid packaging
every single dependency. But nowadays, mold uses whatever dependency it
can find and builds its own if it cannot.
Saves a small amount of compilation time.
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/18881
Signed-off-by: Robert Marko <robimarko@gmail.com>