After bumping sublime3 in #61636 we realized that saving files as root
doesn’t work anymore and somehow the paths weren’t patched by
`libredirect`.
After some debugging it came out that Sublime switched from `posix_spawn(3)`
to `posix_spawnp(3)` to start new processes internally. Since `libredirect`
only handled the former, `/usr/bin/pkexec` stopped being redirected.
Wrapping `posix_spawnp` fixes the problem.
a3667ee6be