How to clear all object keys's value in jq

I want to clear all values from "dependencies" by using jq:

json_string="$(cat <<'END'{"name": "hello","dependencies": {"progress": "^2.0.0","tar": "^6.2.1"  }}END)"

Here is the expected output:

{"name": "hello","dependencies": {"progress": "","tar": ""  }}

I have tried but not work:

# output="$(jq ".dependencies =(.dependencies | keys)" <<< "$json_string")"# echo "output is: $output"output is: {"name": "hello","dependencies": ["progress","tar"  ]}

It only converts the object to an array, but I want it still as object and only clear all values inside all keys.

What's wrong in my jq command and how to fix?