Assert that we can backport to the 3.10 branch. (#453)

Signed-off-by: Mariatta <[email protected]>

* 🐍🌚🤖 Formatted using `black`.

Author: Mariatta

tests/test_backport_pr.py

@@ -3,6 +3,7 @@
 
 from gidgethub import sansio
 
+import pytest
 import redis
 import kombu
 
@@ -98,7 +99,8 @@ async def test_merged_pr_no_backport_label():
     assert not hasattr(gh, "post_url")
 
 
-async def test_merged_pr_with_backport_label():
+@pytest.mark.parametrize("branch", ["3.10", "3.11", "4.0", "3.7"])
+async def test_merged_pr_with_backport_label(branch):
     data = {
         "action": "closed",
         "pull_request": {
@@ -120,14 +122,16 @@ async def test_merged_pr_with_backport_label():
         },
         "https://api.github.com/repos/python/cpython/issues/1/labels": [
             {"name": "CLA signed"},
-            {"name": "needs backport to 3.7"},
+            {"name": f"needs backport to {branch}"},
         ],
     }
 
     gh = FakeGH(getitem=getitem)
     with mock.patch("miss_islington.tasks.backport_task.delay"):
         await backport_pr.router.dispatch(event, gh)
-        assert "I'm working now to backport this PR to: 3.7" in gh.post_data["body"]
+        assert (
+            f"I'm working now to backport this PR to: {branch}" in gh.post_data["body"]
+        )
         assert gh.post_url == "/repos/python/cpython/issues/1/comments"