[False-Positive]: use of function pointers not considered in dead-code analysis

### Describe the issue:

I'm seeing false positives on dead code for these `applyFn` functions:

https://github.com/rainprotocol/rain.lib.interpreter/actions/runs/4844672772/jobs/8633092570#step:6:378

you can see that they are all called in the tests, which is normally enough to make slither happy that the code is not dead

https://github.com/rainprotocol/rain.lib.interpreter/blob/6ed17f7c1fae3656b9444fd99fccaa1f697d77c5/test/LibOp.t.sol

### Code example to reproduce the issue:

Potentially it has something to do with using function pointers in signatures but i really don't know

### Version:

using slither github action so probably latest (0.9.3)

### Relevant log output:

_No response_