docs: fixing a typo

Merge https://github.com/google/adk-python/pull/3975

### Link to Issue or Description of Change

Fixing various typos: see commit diffs for details

**1. Link to an existing issue (if applicable):**

- Closes: N/A
- Related: N/A

**2. Or, if no issue exists, describe the change:**

Fixing various typos: see commit diffs for details

**Problem:**

Improve quality of repo

**Solution:**
Pull this P/R

### Testing Plan

N/A
**Unit Tests:**

- [N/A] I have added or updated unit tests for my change.
- [X] All unit tests pass locally.

**Manual End-to-End (E2E) Tests:**

N/A

### Checklist

- [X] I have read the [CONTRIBUTING.md](https://github.com/google/adk-python/blob/main/CONTRIBUTING.md) document.
- [X] I have performed a self-review of my own code.
- [N/A] I have commented my code, particularly in hard-to-understand areas.
- [N/A] I have added tests that prove my fix is effective or that my feature works.
- [X] New and existing unit tests pass locally with my changes.
- [N/A] I have manually tested my changes end-to-end.
- [N/A] Any dependent changes have been merged and published in downstream modules.

### Additional context

N/A

COPYBARA_INTEGRATE_REVIEW=https://github.com/google/adk-python/pull/3975 from didier-durand:fix-typos-b ca1cba4e7afe99bb60efffb4de79a2bfe8522ea8
PiperOrigin-RevId: 868308215

src/google/adk/runners.py

@@ -937,7 +937,7 @@ class Runner:
     **Events Yielded to Callers:**
     *   **Live Model Audio Events with Inline Data:** Events containing raw
         audio `Blob` data(`inline_data`).
-    *   **Live Model Audio Events with File Data:** Both input and ouput audio
+    *   **Live Model Audio Events with File Data:** Both input and output audio
         data are aggregated into an audio file saved into artifacts. The
         reference to the file is saved in the event as `file_data`.
     *   **Usage Metadata:** Events containing token usage.