Fix T69105: reset the action blend mode to Replace in Bake Action.

This can't be done in Tweak mode since the setting is stored in the
tweaked strip, and the logic for finding it is not exposed to python.

release/scripts/modules/bpy_extras/anim_utils.py

@@ -257,6 +257,9 @@ def bake_action_iter(
 
         atd.action = action
 
+    # Baking the action only makes sense in Replace mode, so force it (T69105)
+    if not atd.use_tweak_mode:
+        atd.action_blend_type = 'REPLACE'
 
     # -------------------------------------------------------------------------
     # Apply transformations to action