feat: add pytest test infrastructure with venv setup and version bump to 1.37.0

- Creates virtual environment activation step in CI workflow before installing dependencies
- Bumps project version from 1.36.0 to 1.37.0 in pyproject.toml
- Documents automated testing addition and version release in CHANGELOG.md

.gitea/workflows/test.yml

@@ -12,6 +12,10 @@ jobs:
       PIP_BREAK_SYSTEM_PACKAGES: 1
     runs-on: ubuntu-latest
     steps:
+    - name: Create virtual environment
+      run: |
+        python -m venv venv
+        . venv/bin/activate
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip