QA tests: link unit_test_framework library only with QA tests.

It fixes a link issue on W10/msys2 when building some .exe files
not related to QA tests, but have the unit_test_framework library linked
without this change..

CMakeLists.txt

@@ -775,9 +775,6 @@ include_directories( SYSTEM ${PIXMAN_INCLUDE_DIR} )
 
 #
 # Find Boost headers and libraries, required.
-if( KICAD_BUILD_QA_TESTS )
-    list( APPEND BOOST_REQUESTED_COMPONENTS unit_test_framework system )
-endif()
 find_package( Boost 1.71.0 REQUIRED COMPONENTS ${BOOST_REQUESTED_COMPONENTS} )
 
 #

qa/CMakeLists.txt

@@ -19,6 +19,9 @@
 # or you may write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 
+list( APPEND BOOST_REQUESTED_COMPONENTS unit_test_framework system )
+find_package( Boost 1.71.0 REQUIRED COMPONENTS ${BOOST_REQUESTED_COMPONENTS} )
+
 include(KiCadQABuildUtils)
 
 if( KICAD_TEST_XML_OUTPUT )

qa/qa_utils/CMakeLists.txt

@@ -38,8 +38,8 @@ add_library( qa_utils STATIC
 
 include_directories( BEFORE ${INC_BEFORE} )
 
-# for some obscure reason, on mingw/msys2 ${Boost_UNIT_TEST_FRAMEWORK_LIBRARY} does not work
-# So use the actual the lib filename:
+# for some obscure reason, on mingw/msys2 Boost::unit_test_framework does not work
+# So use the actual lib filename:
 if( MINGW )
     set( LIBBOOST_UNIT_TEST_LIB libboost_unit_test_framework-mt )
 endif()