When CMP00126 is set to NEW, set(CACHE) doesn't remove regular
variable bindings with the same name as the cache variable.
This introduced an issue in qt_find_package, which called
find_package(CONFIG QUIET) to try and find a package config file, but
did not clean up the non-cache _FOUND variable which is automatically
set to 0 by CMake if no Config file is found.
Make sure to unset both the regular and cache _FOUND variables if either
the package config file was not found, or if none of the provided
targets found even if the Config file was found.
Also move the _DIR cache variable cleaning into the same code block.
Amends 4c31ce68d5
Amends 34b1c1c23c
Fixes: QTBUG-95635
Pick-to: 6.2
Change-Id: I871987217526e0f0a20038a8da52625838e49488
Reviewed-by: Craig Scott <craig.scott@qt.io>
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
72a1e55472