chore: fix store tests on Windows (#2769)

It's just a matter of explicitly closing the database, so that TempDir.removeAll doesn't fail.

test/store/webhook_test.go

@@ -47,4 +47,5 @@ func TestWebhookStore(t *testing.T) {
 	})
 	require.NoError(t, err)
 	require.Equal(t, 0, len(webhooks))
+	ts.Close()
 }