fix(ci): add type stubs for mypy

Author: faeller

.github/workflows/mypy.yml

@@ -10,5 +10,5 @@ jobs:
       - uses: actions/setup-python@v5
         with:
           python-version: "3.12"
-      - run: pip install mypy
+      - run: pip install mypy types-requests types-PyYAML
       - run: mypy src

.gitlab-ci.yml

@@ -12,5 +12,5 @@ mypy:
   stage: lint
   image: python:3.12-slim
   script:
-    - pip install mypy
+    - pip install mypy types-requests types-PyYAML
     - mypy src