Small test fixups

[will-v-pi]

Tests with stdio_usb need the final output to be flushed before exiting (which is done by stdio_deinit_all), otherwise they don't always print PASSED

hardware_sync_spin_lock_test takes too long on RP2040, so increase the timeout as it was close to timing out on RP2350 anyway

[lurch]

IIRC (when I was looking at one of Graham's PRs) there are also some tests that call puts directly rather than using the PICOTEST_ macros. Do those tests also need to be updated to do an explicit stdio_deinit_all()?

Ahh, see my comment here #2897 (comment)

[will-v-pi]

IIRC (when I was looking at one of Graham's PRs) there are also some tests that call puts directly rather than using the PICOTEST_ macros. Do those tests also need to be updated to do an explicit stdio_deinit_all()?

Ahh, see my comment here #2897 (comment)

Those tests don't use stdio_usb, so don't need to call stdio_deinit_all(), so I won't update them