ci: install requirements through dedicated file

Instead of installing codespell manually, install through
'requirements.txt'

Signed-off-by: Alex Fabre <[email protected]>

Author: AlexFabre

.github/workflows/commit-format.yml

@@ -17,7 +17,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install codespell
+        pip install -r requirements.txt
     - name: commit-format 
       run: |
         git fetch --no-tags --depth=1 origin main