coverage xml

see https://github.com/collective/icalendar/actions/runs/9751493239/job/26913191286?pr=678#step:6:78

.github/workflows/tests.yml

@@ -67,6 +67,7 @@ jobs:
       uses: coverallsapp/github-action@v2
       with:
         parallel-finished: true
+        format: cobertura
 
   deploy-tag-to-pypi:
     # only deploy on tags, see https://stackoverflow.com/a/58478262/1320237

tox.ini

@@ -16,6 +16,7 @@ commands =
     coverage run --source=src/icalendar --omit=*/tests/hypothesis/* --omit=*/tests/fuzzed/* --module pytest []
     coverage report
     coverage html
+    coverage xml
 
 [testenv:nopytz]
 # install with dependencies
@@ -34,6 +35,7 @@ commands =
     coverage run --source=src/icalendar --omit=*/tests/hypothesis/* --omit=*/tests/fuzzed/* --module pytest []
     coverage report
     coverage html
+    coverage xml
 
 [testenv:docs]
 deps =