picolibc: Update to version proposed for Zephyr v4.2-branch

We're trying to re-synchronize picolibc bits across Zephyr and the
Zephyr SDK. At this point, SDK 0.17.3 is missing some minor updates
found in the module and the module is missing a commit from the SDK.

Zephyr PR: zephyrproject-rtos/zephyr#94043

Signed-off-by: Keith Packard <[email protected]>

Author: keith-packard