Fix the following issue:

## `jointlimitfrc` / `tendonlimitfrc` sensors aren't supported

I'm trying to run a model in mujoco_warp that uses MuJoCo's `jointlimitfrc` sensor (and I also have a sibling model with a `tendonlimitfrc` sensor). I use these to read out the constraint force whenever a joint or tendon is actively being pushed against its limit — it's part of my safety / contact-detection logic.

Minimal repro:

```python
import mujoco
import mujoco_warp as mjwarp

mjm = mujoco.MjModel.from_xml_path("my_model.xml")
m = mjwarp.put_model(mjm)   # <-- blows up here
```

where `my_model.xml` has something like:

```xml
<sensor>
  <jointlimitfrc joint="my_joint"/>
  <!-- or: <tendonlimitfrc tendon="my_tendon"/> -->
</sensor>
```

`put_model` raises:

```
NotImplementedError: Sensor types [...] not supported.
```

pointing at the limit-force sensor type. The model loads and steps fine in plain MuJoCo — these are standard sensors (`mjSENS_JOINTLIMITFRC` and `mjSENS_TENDONLIMITFRC` on the C side). They just don't appear to be recognized by mujoco_warp yet.

Could support for these two sensor types be added, so their values get written into `sensordata` each step like the other sensors?

Thanks!