Declared test targets with EXCLUDE_FROM_ALL

Closes #181.

test/CMakeLists.txt

@@ -3,12 +3,12 @@ if(NOT TARGET tests)
     set_property(TARGET tests PROPERTY FOLDER _deps)
 endif()
 
-add_library(boost_cobalt_static_tests concepts.cpp util.cpp)
+add_library(boost_cobalt_static_tests EXCLUDE_FROM_ALL concepts.cpp util.cpp)
 target_link_libraries(boost_cobalt_static_tests Boost::cobalt)
 
-add_executable(boost_cobalt_main         main.cpp)
-add_executable(boost_cobalt_main_compile main_compile.cpp)
-add_executable(boost_cobalt_basic_tests
+add_executable(boost_cobalt_main         EXCLUDE_FROM_ALL main.cpp)
+add_executable(boost_cobalt_main_compile EXCLUDE_FROM_ALL main_compile.cpp)
+add_executable(boost_cobalt_basic_tests  EXCLUDE_FROM_ALL
       async_for.cpp test_main.cpp promise.cpp with.cpp op.cpp handler.cpp join.cpp race.cpp this_coro.cpp leaf.cpp
       channel.cpp generator.cpp run.cpp task.cpp gather.cpp wait_group.cpp wrappers.cpp left_race.cpp
       strand.cpp fork.cpp thread.cpp any_completion_handler.cpp detached.cpp monotonic_resource.cpp sbo_resource.cpp)
@@ -19,10 +19,8 @@ target_link_libraries(boost_cobalt_basic_tests  Boost::cobalt Boost::unit_test_f
 
 add_test(NAME boost_cobalt_main COMMAND boost_cobalt_main)
 add_test(NAME boost_cobalt_basic_tests COMMAND boost_cobalt_basic_tests)
-target_compile_features(boost_cobalt PUBLIC cxx_std_20)
 
-
-add_executable(boost_cobalt_experimental test_main.cpp experimental/context.cpp experimental/yield_context.cpp)
+add_executable(boost_cobalt_experimental EXCLUDE_FROM_ALL test_main.cpp experimental/context.cpp experimental/yield_context.cpp)
 target_link_libraries(boost_cobalt_experimental  Boost::cobalt Boost::unit_test_framework Boost::context)
 add_test(NAME boost_cobalt_experimental COMMAND boost_cobalt_experimental)