ota: Import 9f971fba471b from bsd-feature for 20240623

Jun 23, 2024
Fix signal for system-status test. Thanks to Tim van der Molen.
Rewrite if-else chain as switch. Thanks to Andrew Sukach.

May 27, 2024
Spelling fixes and removal of unneeded prototypes and extern.
Thanks to Jonathan Gray.

May 4, 2024
Fixed a use-after-free bug with ARGV for "delete ARGV".
Also ENVtab is no longer global. Thanks to Benjamin Sturz
for spotting the ARGV issue and Todd Miller for the fix.

May 3, 2024:
Remove warnings when compiling with g++. Thanks to Arnold Robbins.