This further aligns the features available on Pico and Pico W boards.
os.dupterm is generally useful, but can still be disabled by a board if
needed. hashlib.sha1 requires mbedtls for the implementation, but that's
always available (due to ucryptolib's requirements). The entire hashlib
module can still be disabled by an individual board if needed.
Fixes issue #7881.
Signed-off-by: Damien George <damien@micropython.org>