Update prettier version in template installation docs

This is now the version used as standard in all Arduino Tooling projects, which the "template" is intended to be used
with.

Author: per1234

workflow-templates/check-prettier-formatting-task.md

@@ -34,7 +34,7 @@ The tool dependencies of this workflow are managed by [npm](https://www.npmjs.co
 Add the dependencies by running this command:
 
 ```text
-npm install --save-dev prettier@^3.3.3
+npm install --save-dev prettier@^3.4.0
 ```
 
 Commit the resulting changes to the `package.json` and `package-lock.json` files.