chore: point to pasteurlabs/mirror-prettier, add toml linting and pyproject.toml validation (#443)

#### Description of changes

Point to frozen Pasteur-hosted mirror-prettier, this enables:
* Support of prettier v3.7.4 which supports the prettier-plugin-toml for
toml linting
* Minimal maintenance and robust security as all updates would happen
only on request

Add validate pyproject pre-commit hook.

We can add these to the pasteur-python-template once happy with here.
 
#### Testing done

- CI (including pre-commit on all files) passes

---------

Co-authored-by: Dion Häfner <dion.haefner@simulation.science>

Author: jpbrodrick89

.pre-commit-config.yaml

@@ -82,9 +82,12 @@ repos:
           '
         additional_dependencies: [uv==0.6.11, --isolated]
 
-  - repo: https://github.com/pre-commit/mirrors-prettier
-    rev: v3.1.0 # Use the latest version
+  - repo: https://github.com/pasteurlabs/mirrors-prettier
+    rev: v3.7.4 # Use the latest version
     hooks:
       - id: prettier
-        types_or: [json, yaml, markdown]
+        types_or: [json, yaml, markdown, toml]
         exclude: CHANGELOG.md
+        additional_dependencies:
+          - prettier@3.7.4
+          - prettier-plugin-toml@2.0.1