Fixes #13541
Follow up to add upgrading notes to #12909
Motivation
12909 is a breaking change and wasn't listed in the upgrading notes
Modifications
Add upgrading notes for this change. The change is subtle and probably affects few users. Some may have worked around it as per #8930 and can optionally remove toJson from expressions, but this is not necessary.
Fixes #13541 Follow up to add upgrading notes to #12909
Motivation
12909 is a breaking change and wasn't listed in the upgrading notes
Modifications
Add upgrading notes for this change. The change is subtle and probably affects few users. Some may have worked around it as per #8930 and can optionally remove
toJson
from expressions, but this is not necessary.Verification
make docs
passes