0.6.0 — repin the C library, whose exec search a consumer could not reach

[Sunrisepeak]

openkal-musl 0.10.0
— the exec search, and the family of answers that were not true (openkal-linux#13).

⚠️⚠️ This repin is not a formality

A version requirement is exact here and nothing floats up, so this package's
pin is the whole of what a C++ consumer can have. Without this release, a program
that writes

openkal-musl         = "0.10.0"
openkal-llvm-runtime = "0.5.0"

does not get the new C library. It does not get the old one either — it gets:

error: dependency 'mcpplibs.openkal-musl' has irreconcilable versions:
  '0.10.0' requested by '<the program>'
  '0.9.0'  requested by 'mcpplibs.openkal-llvm-runtime@0.5.0'

Measured, in a clean sandbox.

⭐ The reporter of openkal-linux#13 builds C++ — their crash reports name
libc++abi and a terminal-interface library — so they reach the C library through
this pin and through nothing else. They were told to change their own line, by
us. This release is what makes the right line exist.

Verified through this package rather than beneath it

std::filesystem::last_write_time on a lock directory, both overloads:

reading a lock directory's mtime (never was broken)      ok
refreshing it -- the overload that actually failed       ok
and the value read back is the one just written          ok

That is the reporter's own case, and the one they read as a failure to read,
because libc++ gives both overloads one name in the message it throws. Reading
was never broken; refreshing was.