bmaptool: upgrade 3.8.0 -> 3.9.0

bmaptool: upgrade 3.8.0 -> 3.9.0

Update to the 3.9.0 version.

This version has switched to use hatch as the build backend, so adjust it
accordingly.

The INSANE_SKIP can now be safely removed as explained by
commit 824009560776 ("bmaptool: temporarily silence the pep517-backend warning").

python3-six is no longer a runtime dependency since bmaptool
commit a67976e80daf ("Remove six from production code"), so remove its
RDEPENDS entry.

Signed-off-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Marcel Ziswiler <marcel@ziswiler.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>