pulsar-client dependency version change

### Description of the bug:

Hi, the installation of dependencies via `poetry install` for https://github.com/google/generative-ai-docs/examples/gemini/python/docs-agent/ according to the tutorial https://ai.google.dev/gemini-api/tutorials/docs-agent currently doesn't work:

```
- Installing pulsar-client (3.6.0): Failed

| Unable to find installation candidates for pulsar-client (3.6.0)
|
| This is likely not a Poetry issue.
|
| - 0 candidate(s) were identified for the package
|
| Solutions:
| Make sure the lockfile is up-to-date. You can try one of the following;
|
| 1. Regenerate lockfile: poetry lock --no-cache --regenerate
| 2. Update package : poetry update --no-cache pulsar-client
|
| If neither works, please first check to verify that the pulsar-client has published wheels available from your configured source that are compatible with your environment- ie. operating system, architecture (x86_64, arm64 etc.), python interpreter.
```

It seems that only pulsar-client 3.6.1 is available from PyPI (https://pypi.org/project/pulsar-client/#history). Thanks!

### Actual vs expected behavior:

Expected: `poetry install` installs project dependencies. Actual: Installation fails due to missing package version.

### Any other information you'd like to share?

I tried adding `pulsar-client = "^3.6.1"` to pyproject.toml and regenerating the lock file via `poetry lock`, but this takes forever on my machine, so not a viable solution.