refactor(postgres): Remove two more deprecated cfg flag uses (from docstrings)

Signed-off-by: Joshua Potts <[email protected]>

Author: iamjpotts

sqlx-core/src/acquire.rs

@@ -15,7 +15,6 @@ use std::ops::{Deref, DerefMut};
 ///
 /// ```rust
 /// # use sqlx::{Acquire, postgres::Postgres, error::BoxDynError};
-/// # #[cfg(any(postgres_9_6, postgres_15))]
 /// async fn run_query<'a, A>(conn: A) -> Result<(), BoxDynError>
 /// where
 ///     A: Acquire<'a, Database = Postgres>,
@@ -35,7 +34,6 @@ use std::ops::{Deref, DerefMut};
 /// ```rust
 /// # use std::future::Future;
 /// # use sqlx::{Acquire, postgres::Postgres, error::BoxDynError};
-/// # #[cfg(any(postgres_9_6, postgres_15))]
 /// fn run_query<'a, 'c, A>(conn: A) -> impl Future<Output = Result<(), BoxDynError>> + Send + 'a
 /// where
 ///     A: Acquire<'c, Database = Postgres> + Send + 'a,