CI: Fix test workflow re. versioningit

Author: amotl

.github/workflows/tests.yml

@@ -36,6 +36,8 @@ jobs:
 
     - name: Acquire sources
       uses: actions/checkout@v3
+      with:
+        fetch-depth: 0
 
     # https://github.com/docker-practice/actions-setup-docker
     # - name: Install Docker