Fix ci for local workflow calls

Author: eomielan

.github/workflows/ci.yml

@@ -34,9 +34,9 @@ jobs:
         run: pip install pytest
 
       - name: Build project
-        working-directory: ${{ inputs.working-directory }}
+        working-directory: ${{ inputs.working-directory || '.' }}
         run: make
 
       - name: Run tests
-        working-directory: ${{ inputs.working-directory }}/src/test
+        working-directory: ${{ inputs.working-directory || '.' }}/src/test
         run: pytest