Mustache tags null values are returning "null" strings again

What happened?

I am familiar with this issue which was resolved back in 2019, but there seems to have been a regression.

I haven't been using it in projects until yesterday, and I found out that mustache tags encountering null values are returning "null" strings again.

Steps to reproduce

For example, adding recommended tags in your task instructions, like:

`man_made=bridge`
`name=`{{name}}
`alt_name=`{{alt_name}}

may return something like, null values return "null" strings.

man_made=bridge
name=Xyz Bridge
alt_name=null

rather than the previous behavior I expected:

man_made=bridge
name=Xyz Bridge
alt_name=

Environment

Firefox, Vivaldi

Additional information

No response