Conan: simplify Conan recipe

The qt-conan-common package contains shared functionality
for recipes that should be used:
 - environment wrap during the build()
 - package_info() is generic for all recipes

Move the _build() out from the class so that it is usable for
the callback from qt-conan-common package.

Simplify how the Qt module version and prerelease tag is
read from .cmake.conf and how the file is being referenced.
As the .cmake.conf is included in the "exports" it will
be always present next to the recipe:
  - in .git source tree
  - in Conan cache

Pick-to: 6.2
Change-Id: I4bbd683f7b49151620397e0b7f4272929a93c060
Reviewed-by: Toni Saario <toni.saario@qt.io>

0 files changed, 0 insertions, 0 deletions