Fix code block indentation formatting in CONTRIBUTING.md

- Align step 6 code block with other steps
- Remove extra blank line before step 8 code block
- Improve overall formatting consistency

Author: felixweinberger

CONTRIBUTING.md

@@ -13,10 +13,9 @@ Thank you for your interest in contributing to the MCP Python SDK! This document
 uv sync --frozen --all-extras --dev
 ```
 6. Set up pre-commit hooks:
-
-   ```bash
-   uv tool install pre-commit --with pre-commit-uv --force-reinstall
-   ```
+```bash
+uv tool install pre-commit --with pre-commit-uv --force-reinstall
+```
 
 ## Development Workflow
 
@@ -51,7 +50,6 @@ uv run scripts/update_readme_snippets.py
 ```
 
 8. (Optional) Run pre-commit hooks on all files:
-
 ```bash
 pre-commit run --all-files
 ```