Found docs updates needed from ADK python release v2.6.2 to v2.6.3

Compare link: https://github.com/google/adk-python/compare/v2.6.2...v2.6.3

### 1. **Document the new `--with_cloud_run_sandbox` flag for Python Cloud Run deployment**

**Doc file**: deploy/cloud-run.md

**Current state**:
> * `--with_ui`: (Optional) If included, deploys the ADK dev UI alongside the agent API server. By default, only the API server is deployed.
> * `--temp_folder TEXT`: (Optional) Specifies a directory for storing intermediate files generated during the deployment process. Defaults to a timestamped folder in the system's temporary directory. *(Note: This option is generally not needed unless troubleshooting issues).*
> * `--help`: Show the help message and exit.

**Proposed Change**:
> * `--with_ui`: (Optional) If included, deploys the ADK dev UI alongside the agent API server. By default, only the API server is deployed.
> * `--with_cloud_run_sandbox`: (Optional) Whether to enable the Cloud Run sandbox for code execution. Requires the 'gcloud beta run deploy' release track. Note: Prior to v2.6.3, this was enabled by default.
> * `--temp_folder TEXT`: (Optional) Specifies a directory for storing intermediate files generated during the deployment process. Defaults to a timestamped folder in the system's temporary directory. *(Note: This option is generally not needed unless troubleshooting issues).*
> * `--help`: Show the help message and exit.

**Reasoning**:
The ADK Python CLI has introduced a new optional flag `--with_cloud_run_sandbox` for the `adk deploy cloud_run` command. Prior to v2.6.3, Cloud Run deployments implicitly used the beta track and the sandbox-launcher. Now, deployments use the GA track by default and the sandbox launcher is disabled unless this flag is explicitly set. This behavior change and new flag must be documented.

**Reference**: src/google/adk/cli/cli_tools_click.py and src/google/adk/cli/cli_deploy.py

Start with deploy/cloud-run.md and compare the v2.6.2 to v2.6.3 behavior described in src/google/adk/cli/cli_tools_click.py and src/google/adk/cli/cli_deploy.py. Document the --with_cloud_run_sandbox flag, its beta-track requirement, and changed default behavior. Done means the deployment option list accurately reflects v2.6.3.

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