fix(kmod): KUNIT_BUILD applied only for kunit tests objects files

[Koichi98]

Description

agnocast.koもKUNIT_BUILDフラグでビルドされてしまっていたのでその修正。

Related links

#453

How was this PR tested?

• Autoware (required)
• bash scripts/e2e_test_1to1_with_ros2sub (required)
• bash scripts/e2e_test_2to2 (required)
• sample application

Notes for reviewers

[github-actions]

------------------------------------------------------------------------------
                           GCC Code Coverage Report
Directory: .
------------------------------------------------------------------------------
File                                       Lines    Exec  Cover   Missing
------------------------------------------------------------------------------
src/agnocastlib/include/agnocast/agnocast.hpp
                                               4       4   100%   
src/agnocastlib/include/agnocast/agnocast_callback_info.hpp
                                              25      22    88%   91,93-94
src/agnocastlib/include/agnocast/agnocast_executor.hpp
                                               1       1   100%   
src/agnocastlib/include/agnocast/agnocast_publisher.hpp
                                              89      57    64%   95,114-116,127,133,137,145-147,150,154-156,163-164,167-169,172-173,176,181,208-209,214-215,218-220,224-225
src/agnocastlib/include/agnocast/agnocast_smart_pointer.hpp
                                              47      47   100%   
src/agnocastlib/src/agnocast.cpp              57      10    17%   19,22,24-30,34-35,38-42,46-47,51-54,57,60,62,65,67-68,73,75-77,80-83,86,88-94,97,107-108
src/agnocastlib/src/agnocast_callback_info.cpp
                                              17      14    82%   29-31
src/agnocastlib/src/agnocast_component_container.cpp
                                              12       0     0%   5,7-8,11-13,16,18-20,22-23
src/agnocastlib/src/agnocast_component_container_mt.cpp
                                              25       0     0%   7,11-12,14-16,18-23,25-27,29-31,34-35,37-39,41-42
src/agnocastlib/src/agnocast_executor.cpp
                                             104      79    76%   20-21,49,60-62,80-83,86,102-104,117-119,129-131,136-139,174
src/agnocastlib/src/agnocast_multi_threaded_executor.cpp
                                              61      53    86%   20,25-26,33,39-41,110
src/agnocastlib/src/agnocast_publisher.cpp
                                              56       7    12%   10,12,23,26,31,35,37-46,49,52,57-64,73-74,76-79,81-84,86,91,95-96,101,104,106-111,114
src/agnocastlib/src/agnocast_single_threaded_executor.cpp
                                              25      21    84%   16,26-28
src/agnocastlib/src/agnocast_smart_pointer.cpp
                                              18       0     0%   6,9-16,20,23-30
src/agnocastlib/src/agnocast_subscription.cpp
                                              52       9    17%   6-7,9,12,15,19-30,33-37,40,43,47-52,54-59,61,63,66,70-71,73-74
src/agnocastlib/src/agnocast_utils.cpp        29      26    89%   63,65-66
------------------------------------------------------------------------------
TOTAL                                        622     350    56%
------------------------------------------------------------------------------