stonehenge: install marge bot and renovate bot

pkgs/marge-bot/patches/allow-self-merges.patch

@@ -0,0 +1,38 @@
+diff --git i/marge/job.py w/marge/job.py
+index ae707c0..404fb18 100644
+--- i/marge/job.py
++++ w/marge/job.py
+@@ -616,8 +616,6 @@ def _get_reviewer_names_and_emails(
+     self_reviewed = {commit["author_email"] for commit in commits} & {
+         user.email for user in users
+     }
+-    if self_reviewed and len(users) <= 1:
+-        raise CannotMerge("Commits require at least one independent reviewer.")
+     return [f"{user.name} <{user.email}>" for user in users]
+ 
+ 
+diff --git i/tests/test_approvals.py w/tests/test_approvals.py
+index a65ae95..ecb38a4 100644
+--- i/tests/test_approvals.py
++++ w/tests/test_approvals.py
+@@ -168,20 +168,6 @@ class TestApprovals:
+             commits=[], approvals=self.approvals, api=self.api
+         ) == ["Administrator <root@localhost>", "Roger Ebert <ebert@example.com>"]
+ 
+-    @patch("marge.user.User.fetch_by_id")
+-    def test_approvals_fails_when_same_author(self, user_fetch_by_id):
+-        info = dict(INFO, approved_by=list(INFO["approved_by"]))
+-        del info["approved_by"][1]
+-        approvals = Approvals(self.api, info)
+-        user_fetch_by_id.side_effect = lambda id, _: marge.user.User(
+-            self.api, USERS[id]
+-        )
+-        commits = [{"author_email": "root@localhost"}]
+-        with pytest.raises(CannotMerge):
+-            _get_reviewer_names_and_emails(
+-                commits=commits, approvals=approvals, api=self.api
+-            )
+-
+     @patch("marge.user.User.fetch_by_id")
+     def test_approvals_succeeds_with_independent_author(self, user_fetch_by_id):
+         user_fetch_by_id.side_effect = lambda id, _: marge.user.User(