Clean up build2-toolchain intermediate binaries

Remove build2-toolchain intermediate binaries during cleanup.

Author: mcserep

.github/scripts/ubuntu-22.04/postcompile_build.sh

@@ -8,3 +8,4 @@ echo "CMAKE_PREFIX_PATH=${INSTALL_PATH}/odb:$CMAKE_PREFIX_PATH" >> $GITHUB_ENV
 # Clean up dependency sources and intermediate binaries to save space
 rm -rf ${DOWNLOAD_PATH}/odb
 rm -rf ${INSTALL_PATH}/build2
+rm -rf ./build2-toolchain-*