Build Boost via its own CMake instead of copying headers

cpp/CMakeLists.txt sets CMP0167 NEW (Boost CONFIG mode), so
find_package(Boost) requires an installed Boost CMake package
(BoostConfig.cmake etc.), not just headers on the include path -
dropping a bare header tree into /usr/local/include left CMake unable
to find a Boost config file at all.

Build Boost from its official 1.87.0 source release using its own
CMake support, restricted via BOOST_INCLUDE_LIBRARIES to the libraries
DOLFINx actually includes (unordered, sort, uuid, lexical_cast,
algorithm, container_hash, multiprecision) plus their transitive
dependencies, which Boost's CMake resolves automatically.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: jhale

.github/workflows/build-wheels.yml

@@ -173,7 +173,12 @@ jobs:
             dnf -y update &&
             dnf -y install git hdf5-mpich-devel make \
               mpich-devel ninja-build openblas-devel pugixml-devel spdlog-devel &&
-            curl -L https://archives.boost.io/release/1.87.0/source/boost_1_87_0.tar.gz | tar -xz --strip-components=1 -C /usr/local/include boost_1_87_0/boost &&
+            curl -L https://archives.boost.io/release/1.87.0/source/boost_1_87_0.tar.gz | tar -xz &&
+            cmake -G Ninja -S boost_1_87_0/ -B boost-build-dir/ \
+              -DCMAKE_BUILD_TYPE=Release \
+              -DBOOST_INCLUDE_LIBRARIES="unordered;sort;uuid;lexical_cast;algorithm;container_hash;multiprecision" &&
+            cmake --build boost-build-dir/ &&
+            cmake --install boost-build-dir/ &&
             ln -s /usr/include/mpich-$(arch) /usr/lib64/mpich/include &&
             mkdir -p scotch && curl -L https://gitlab.inria.fr/scotch/scotch/-/archive/v7.0.12/scotch-v7.0.12.tar.bz2 | tar -xj --strip-components=1 -C scotch &&
             cmake -G Ninja -S scotch/ -B scotch-build-dir/ \