Added basic python jobs.

python/base.yml

+variables:
+  PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
+
+default:
+  cache:
+    paths:
+      - .cache/pip
+      - .venv
+  before_script:
+    - python -m venv .venv
+    - source .venv/bin/activate
+    - pip install -e ".[test]"

python/build.yml

+build:
+  script:
+    - pyproject-build

python/lint.yml

+lint:
+  script:
+    - ruff check .

python/test.yml

+tests:
+  script:
+    - coverage run -m pytest
+    - coverage report
+  coverage: '/(?i)total.*? (100(?:\.0+)?\%|[1-9]?\d(?:\.\d+)?\%)$/'