Update gitpython version in "Deploy Website" template installation docs

[email protected] is now the version used as standard in all Arduino Tooling projects.

Author: per1234

workflow-templates/deploy-mkdocs-versioned-poetry.md

@@ -33,7 +33,7 @@ See the ["Deploy Website" workflow (MkDocs, Poetry) documentation](deploy-mkdocs
 
 1. Run this command:
    ```
-   poetry add --dev "gitpython@^3.1.27" "mike@^1.1.2"
+   poetry add --dev "gitpython@^3.1.29" "mike@^1.1.2"
    ```
 1. Commit the resulting `pyproject.toml` and `poetry.lock` files.