Issue

claude opus 4.6 made these changes. of course reviewed by me;) they make sense.

• make the conan installation path explicit, i.e. where it looks for the conanfile.py
• same for the path to conan_toolchain.cmake, also change its order to come after installing the packages, which is the process providing the info actually going into that file
• use include rather than set for the toolchain file, which will immediately set all important paths for cmake. it works in upstream osrm bcs it's happening in the same cmake project. if used in parent projects cmake config is already done by the time it tries to set the toolchain file, so it's too late and nothing would change.

Tasklist

• self-review code for correctness and following the coding guidelines
• add tests (see testing)
• update relevant wiki pages
• CHANGELOG.md entry (see how to)
• review
• adjust for comments

Fixes #7439