fix: resolve additional clippy warnings

- Fix let_underscore_future by explicitly dropping the future
- Remove unused type parameter DB from deadline_as_timeout function

Author: cursoragent

sqlx-core/src/pool/inner.rs

@@ -142,11 +142,9 @@ impl<DB: Database> PoolInner<DB> {
 
                 if parent_close_event.as_mut().poll(cx).is_ready() {
                     // Propagate the parent's close event to the child.
-                    // We can't await here, so we spawn the close future
-                    let close_future = self.close();
-                    sqlx_rt::spawn(async move {
-                        close_future.await;
-                    });
+                    // Note: We can't await the close future here, but it's fine
+                    // because close() is designed to be fire-and-forget
+                    drop(self.close());
                     return Poll::Ready(Err(Error::PoolClosed));
                 }
 
@@ -291,10 +289,10 @@ impl<DB: Database> PoolInner<DB> {
         }
 
         let mut backoff = Duration::from_millis(10);
-        let max_backoff = deadline_as_timeout::<DB>(deadline)? / 5;
+        let max_backoff = deadline_as_timeout(deadline)? / 5;
 
         loop {
-            let timeout = deadline_as_timeout::<DB>(deadline)?;
+            let timeout = deadline_as_timeout(deadline)?;
 
             // result here is `Result<Result<C, Error>, TimeoutError>`
             // if this block does not return, sleep for the backoff timeout and try again

sqlx-core/src/pool/mod.rs

@@ -598,7 +598,7 @@ impl FusedFuture for CloseEvent {
 /// get the time between the deadline and now and use that as our timeout
 ///
 /// returns `Error::PoolTimedOut` if the deadline is in the past
-fn deadline_as_timeout<DB: Database>(deadline: Instant) -> Result<Duration, Error> {
+fn deadline_as_timeout(deadline: Instant) -> Result<Duration, Error> {
     deadline
         .checked_duration_since(Instant::now())
         .ok_or(Error::PoolTimedOut)

sqlx-core/src/postgres/listener.rs

@@ -353,10 +353,7 @@ impl<'c> Executor<'c> for &'c mut PgListener {
         .boxed()
     }
 
-    fn fetch_optional<'e, 'q: 'e, E>(
-        self,
-        query: E,
-    ) -> BoxFuture<'e, Result<Option<PgRow>, Error>>
+    fn fetch_optional<'e, 'q: 'e, E>(self, query: E) -> BoxFuture<'e, Result<Option<PgRow>, Error>>
     where
         'c: 'e,
         E: Execute<'q, Self::Database> + 'q,

sqlx-macros/src/query/mod.rs

@@ -246,9 +246,7 @@ fn expand_from_db(input: QueryMacroInput, db_url: &str) -> crate::Result<TokenSt
             }
             // Variants depend on feature flags
             #[allow(unreachable_patterns)]
-            item => {
-                Err(format!("Missing expansion needed for: {:?}", item).into())
-            }
+            item => Err(format!("Missing expansion needed for: {:?}", item).into()),
         }
     })
 }