Pass a reference to TestAppContext in tests

This allows us to drop the context *after* we ran all futures to
completion and that's crucial otherwise we'll never drop entities
and/or flush effects.

crates/server/src/db.rs

@@ -627,7 +627,7 @@ pub mod tests {
     use util::post_inc;
 
     #[gpui::test]
-    async fn test_get_users_by_ids(cx: TestAppContext) {
+    async fn test_get_users_by_ids(cx: &mut TestAppContext) {
         for test_db in [TestDb::postgres(), TestDb::fake(cx.background())] {
             let db = test_db.db();
 
@@ -667,7 +667,7 @@ pub mod tests {
     }
 
     #[gpui::test]
-    async fn test_recent_channel_messages(cx: TestAppContext) {
+    async fn test_recent_channel_messages(cx: &mut TestAppContext) {
         for test_db in [TestDb::postgres(), TestDb::fake(cx.background())] {
             let db = test_db.db();
             let user = db.create_user("user", false).await.unwrap();
@@ -703,7 +703,7 @@ pub mod tests {
     }
 
     #[gpui::test]
-    async fn test_channel_message_nonces(cx: TestAppContext) {
+    async fn test_channel_message_nonces(cx: &mut TestAppContext) {
         for test_db in [TestDb::postgres(), TestDb::fake(cx.background())] {
             let db = test_db.db();
             let user = db.create_user("user", false).await.unwrap();