Fixes for custom dependency install failing due to typo in template generator (#3197)

# Description

The [template
generator](https://isaac-sim.github.io/IsaacLab/main/source/overview/developer-guide/template.html)
is involved when project / task is created using ```./isaaclab.sh -n
[Project Name]```. Inside the ```source``` directory in
```config/extension.toml``` file there is a provision to add custom apt
or ros_ws dependency as mentioned
[here](https://isaac-sim.github.io/IsaacLab/main/source/overview/developer-guide/development.html#custom-extension-dependency-management)
which is current failing.

The problem is result of a typo in the template generator extension
config file which is current ```[isaaclab_settings]``` and should be
```[isaac_lab_settings]``` instead. The file is located at:
```
IsaacLab/tools/template/templates/extension/config/extension.toml
```

Fixes #3196 

## Type of change

- Breaking change (fix or feature that would cause existing
functionality to not work as expected)

## Screenshots

| Before | After |
| ------ | ----- |
| <img width="591" height="201" alt="image"
src="https://github.com/user-attachments/assets/57daa5a7-ba26-4f21-8749-14123470817e"
/> | <img width="591" height="201" alt="image"
src="https://github.com/user-attachments/assets/ddb129ad-cf84-474f-b87f-da5158981f56"
/>|

## 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
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] 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

---------

Signed-off-by: Mayank Mittal <[email protected]>
Co-authored-by: Mayank Mittal <[email protected]>

Author: trushant05

CONTRIBUTORS.md

@@ -133,6 +133,7 @@ Guidelines for modifications:
 * Stefan Van de Mosselaer
 * Stephan Pleines
 * Tiffany Chen
+* Trushant Adeshara
 * Tyler Lum
 * Victor Khaustov
 * Virgilio Gómez Lambo

tools/template/templates/extension/config/extension.toml

@@ -25,7 +25,7 @@ keywords = ["extension", "template", "isaaclab"]
 [[python.module]]
 name = "{{ name }}"
 
-[isaaclab_settings]
+[isaac_lab_settings]
 # TODO: Uncomment and list any apt dependencies here.
 #       If none, leave it commented out.
 # apt_deps = ["example_package"]