[Bug]: Library call function is not an instance of `Function`

### Describe the issue:

Library call function is not an instance of `Function`
Related with this library call here https://github.com/code-423n4/2023-01-timeswap/blob/ef4c84fb8535aad8abd6b67cc45d994337ec4514/packages/v2-option/src/TimeswapV2Option.sol#L112

### Code example to reproduce the issue:

```
git clone https://github.com/code-423n4/2023-01-timeswap
yarn
cd v2-token
slither .
```

### Version:

0.9.2

### Relevant log output:

```shell
File "/Users/alpharush/tob/slither/slither/core/cfg/node.py", line 920, in _find_read_write_call
assert isinstance(ir.function, Function)
AssertionError
```