Add missing example dependencies and remove dataset softlink (rerun-i…

…o#4501)

### What
Add missing `requests` dependency and remove accidentally added dataset
softlink.

### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested the web demo (if applicable):
  * Full build: [app.rerun.io](https://app.rerun.io/pr/4501/index.html)
* Partial build:
[app.rerun.io](https://app.rerun.io/pr/4501/index.html?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
- Useful for quick testing when changes do not affect examples in any
way
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG

- [PR Build Summary](https://build.rerun.io/pr/4501)
- [Docs
preview](https://rerun.io/preview/d49305b8fb1ac7f70ac6b3e45c6e1f09ee6a73bb/docs)
<!--DOCS-PREVIEW-->
- [Examples
preview](https://rerun.io/preview/d49305b8fb1ac7f70ac6b3e45c6e1f09ee6a73bb/examples)
<!--EXAMPLES-PREVIEW-->
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

examples/python/lidar/requirements.txt

@@ -1,4 +1,5 @@
 matplotlib
 numpy
 nuscenes-devkit
+requests
 rerun-sdk

examples/python/nuscenes/requirements.txt

@@ -1,4 +1,5 @@
 matplotlib
 numpy
 nuscenes-devkit
+requests
 rerun-sdk