Geometry Nodes: enable closure regression tests

Some special care had to be taken because these tests require an experimental
feature to be turned on to work.

Pull Request: https://projects.blender.org/blender/blender/pulls/137414

tests/python/CMakeLists.txt

@@ -1021,6 +1021,7 @@ endif()
 if(TEST_SRC_DIR_EXISTS)
   set(geo_node_tests
     attributes
+    closure
     curve_primitives
     curves
     curves/interpolate_curves

tests/python/geo_node_test.py

@@ -5,10 +5,18 @@
 
 import os
 import sys
+import bpy
 
 sys.path.append(os.path.dirname(os.path.realpath(__file__)))
 from modules.mesh_test import BlendFileTest
 
+if "closure" in bpy.data.filepath:
+    if bpy.app.version_cycle == "alpha":
+        bpy.context.preferences.experimental.use_bundle_and_closure_nodes = True
+    else:
+        print("Skipped because bundles and closures are still experimental.")
+        sys.exit(0)
+
 geo_node_test = BlendFileTest("test_object", "expected_object", threshold=1e-4)
 result = geo_node_test.run_test()