Only consider test dependencies of requested libraries

Don't check the test/example folders for (implicit) dependencies as
BUILD_TESTING for those is disabled.

Author: Flamefire

include/BoostRoot.cmake

@@ -298,7 +298,8 @@ function(__boost_gather_dependencies var input_list with_test)
 
       __boost_scan_dependencies(${lib} new_deps "")
       list(APPEND cur_dependencies ${new_deps})
-      if(with_test)
+      # Only consider test dependencies of the input libraries, not transitively as those tests aren't build
+      if(with_test AND lib IN_LIST input_list)
           __boost_scan_dependencies(${lib} new_deps "test")
           list(APPEND cur_dependencies ${new_deps})
           __boost_scan_dependencies(${lib} new_deps "example")
@@ -326,7 +327,7 @@ if(BOOST_INCLUDE_LIBRARIES)
   list(REMOVE_DUPLICATES BOOST_INCLUDE_LIBRARIES)
   __boost_gather_dependencies(__boost_dependencies "${BOOST_INCLUDE_LIBRARIES}" OFF)
   if(BUILD_TESTING)
-    __boost_gather_dependencies(__boost_test_dependencies "${BOOST_INCLUDE_LIBRARIES};${__boost_dependencies}" ON)
+    __boost_gather_dependencies(__boost_test_dependencies "${BOOST_INCLUDE_LIBRARIES}" ON)
     list(REMOVE_ITEM __boost_test_dependencies ${__boost_dependencies})
   endif()
 else()