Add unit tests to build-and-publish workflow

- Add unit-tests job that runs before build-and-publish
- Tests run on Ubuntu with Python 3.8 (same as build-and-test.yaml)
- Add needs: unit-tests dependency to ensure tests pass before publishing
- Prevents publishing broken code to PyPi
- Tested locally: 287 tests pass successfully

Author: sunnywu

.github/workflows/build-and-publish.yaml

@@ -19,8 +19,32 @@ on:
         default: 'CRITICAL,HIGH'
 
 jobs:
+  unit-tests:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.8"]
+    
+    steps:
+    - uses: actions/checkout@v4
+    
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v4
+      with:
+        python-version: ${{ matrix.python-version }}
+    
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install -e .[dev]
+    
+    - name: Run unit tests
+      run: |
+        python -m unittest tests/*.py
+
   build-and-pubish:
     name: Build and publish Python packages to PyPi
+    needs: unit-tests
     uses: IABTechLab/uid2-shared-actions/.github/workflows/shared-publish-to-pypi-versioned.yaml@v3
     with:
       release_type: ${{ inputs.release_type }}