# Description

Previously, the configclass instance did not properly parse
classmethods. For instance, the following would fail:

```python
from __future__ import annotations

"""Launch Isaac Sim Simulator first."""

from omni.isaac.lab.app import AppLauncher

# launch omniverse app
app_launcher = AppLauncher(headless=True)

"""Rest everything follows."""

from omni.isaac.lab.utils.configclass import configclass


@configclass
class DummyClass:

    a: int = 5

    def instance_method(self):
        print("Value of a: ", self.a)

    @classmethod
    def class_method(cls, value: int) -> DummyClass:
        return cls(a=value)


cfg = DummyClass()

# check all methods are callable
cfg.instance_method()
new_cfg1 = cfg.class_method(20)

# create the same config instance using class method
new_cfg2 = DummyClass.class_method(20)
```

This MR fixes the checks to make sure class-methods remain bound to the
class and do not become instance variables.

## Type of change

- Bug fix (non-breaking change which fixes an issue)

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there