Trying to use multitool itself to update from bazel

I'm trying to wrap my head around how I can update multitool itself with bazel

I have it declared here -> https://github.com/malkia/opentelemetry-cpp/blob/main/multitool.lock.json

and I did quite a lot of (stupid) stuff in here -> https://github.com/malkia/opentelemetry-cpp/blob/main/BUILD#L517

but I think it boils downto not able (in one step) to somehow tell bazel - this file is both input and output (because multitool updates the multitool.lock.json, not like read from one place, write to another).

I guess solution would be to have a wrapper (.py, shell script, or something in .bzl?) - but wondering if I missed something obvious here.

Thanks!