Fix T73921: Eevee volume render test memory leak in Mantaflow

Fixed memory leak that showed up after the original issue (crash) had been fixed in 93ac4709eb. The fix ensures that light cache bakes free up GPU smoke textures and the smoke domain list correctly.

This commit also removes the workaround (f3a33a9298) that disabled light cache bakes for fluid objects.

tests/python/eevee_render_tests.py

@@ -35,13 +35,6 @@ def setup():
         # mat.use_screen_refraction = True
         mat.use_sss_translucency = True
 
-    # Workaround for crash with Mantaflow (T73921).
-    use_light_cache_bake = True
-    for ob in bpy.data.objects:
-        for mod in ob.modifiers:
-            if mod.type == 'FLUID':
-                use_light_cache_bake = False
-
     cubemap = None
     grid = None
     # Does not work in edit mode
@@ -86,8 +79,7 @@ def setup():
     eevee.gi_visibility_resolution = '16'
     eevee.gi_irradiance_smoothing = 0
 
-    if use_light_cache_bake:
-        bpy.ops.scene.light_cache_bake()
+    bpy.ops.scene.light_cache_bake()
 
 
 # When run from inside Blender, render and exit.