Fix FTBFS caused by nodejs setting O_NONBLOCK on the build log pipe

Nodejs (used by the CSS minimizer) sets O_NONBLOCK on its output streams
during execution but doesn't set them back afterwards. If make later
writes a lot of data to the log at once, it might fail to do so with
EAGAIN instead of blocking. This commit prevents this by creating a
temporary pipe which nodejs runs in and set O_NONBLOCK on without
breaking the rest of the build.

See: https://github.com/nodejs/node/issues/14752
Closes: #895154