Tests: fix memory leak of GHOST system paths

Dispose of GHOST system paths when tearing down `BlendfileLoadingBaseTest`
and some other test cases. This prevents a memory leak.

A better solution would be to rework Blender's initialisation & teardown
structure, but that's outside the scope of this fix.

No functional changes to Blender.

source/blender/blenkernel/intern/layer_test.cc

@@ -33,6 +33,8 @@
 
 #include "RNA_access.h"
 
+#include "GHOST_Path-api.h"
+
 namespace blender::bke::tests {
 
 TEST(view_layer, aov_unique_names)
@@ -94,6 +96,7 @@ TEST(view_layer, aov_unique_names)
   IMB_exit();
   BKE_appdir_exit();
   CLG_exit();
+  GHOST_DisposeSystemPaths();
 }
 
 static void test_render_pass_conflict(Scene *scene,
@@ -173,6 +176,7 @@ TEST(view_layer, aov_conflict)
   IMB_exit();
   BKE_appdir_exit();
   CLG_exit();
+  GHOST_DisposeSystemPaths();
 }
 
 }  // namespace blender::bke::tests

source/blender/blenloader/CMakeLists.txt

@@ -34,6 +34,7 @@ set(INC
   ../sequencer
   ../windowmanager
   ../../../intern/clog
+  ../../../intern/ghost
   ../../../intern/guardedalloc
 
   # for writefile.c: dna_type_offsets.h

source/blender/blenloader/tests/blendfile_loading_base_test.cc

@@ -48,6 +48,8 @@
 #include "WM_api.h"
 #include "wm.h"
 
+#include "GHOST_Path-api.h"
+
 #include "CLG_log.h"
 
 void BlendfileLoadingBaseTest::SetUpTestCase()
@@ -93,6 +95,7 @@ void BlendfileLoadingBaseTest::TearDownTestCase()
   RNA_exit();
 
   DEG_free_node_types();
+  GHOST_DisposeSystemPaths();
   DNA_sdna_current_free();
   BLI_threadapi_exit();