FindBoost: Add support for Boost 1.86
Update the list of known versions.
Run the command
cmake -DBOOST_DIR=/path/to/boost_1_86_0 \
-P Utilities/Scripts/BoostScanDeps.cmake
to extract dependencies from the 1.86.0 source tree. They are the same as 1.85's dependencies, so just update the version check for warning about newer versions.
Fixes: #26433 (closed)
Backport: release
Manual-backport: release-3.30