Since `postject-api.h` gets compiled into Node.js, it makes more sense
to put it in the `deps` directory instead of `test/fixtures`.
Refs: https://github.com/nodejs/node/pull/45038#discussion_r1100752158
Signed-off-by: Darshan Sen <raisinten@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/46582
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Michael Dawson <midawson@redhat.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>