Setup minimal unit testing workflow

Reusing what we had before, later we can test the full matrix we expect.

Author: Michael Vasseur

.github/workflows/unit-tests.yml

@@ -8,7 +8,7 @@ on:
       - '[0-9]+.[0-9]+'
 
 jobs:
-  check-static-codecov:
+  unit-tests:
     services:
       sqlserver:
         image: mariadb
@@ -19,6 +19,10 @@ jobs:
         options: --health-cmd="healthcheck.sh --connect --innodb_initialized" --health-interval=10s --health-timeout=5s --health-retries=3
     container:
       image: domjudge/gitlabci:24.04
+    strategy:
+      matrix:
+        PHPVERSION: [8.1]
+        TEST: [UNIT]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4