* osx: fix inconsistent use of the macro `TARGET_OS_OSX`
Fixed the build error on iOS:
```
httplib.h:3583:3: error: unknown type name 'CFStringRef'
870 | CFStringRef hostname_ref = CFStringCreateWithCString(
```
Note, `TARGET_OS_OSX` is defined but is 0 when `TARGET_OS_IOS` is 1,
and vise versa. Hence, `TARGET_OS_MAC` should have been used, that is
set to 1 for the both targets.
* improve: non-blocking getaddrinfo() for all mac target variants
`TARGET_OS_MAC` should have been used, that is set to 1 for all other
targets: OSX, IPHONE (IOS, TV, WATCH, VISION, BRIDGE), SIMULATOR,
DRIVERKIT.
