sync: show the target athlete's name, not the session's own

/sync/{athlete_id} always rendered 'Sync: <session.display_name>',
even when athlete_id (now possibly a foreign athlete, see the
previous 'allow syncing athletes other than the current session'
change) differed from the session's own athlete. The header now

src/db.rs

@@ -122,54 +122,6 @@ pub async fn session_athlete(db: &PgPool, token: &str) -> Result<Option<SessionA
     }))
 }
 
-/// Return all locally known athletes that use the same credential as the
-/// current session.
-///
-/// Intervals.icu does not expose an API endpoint that enumerates every
-/// athlete a credential can access. Therefore this is the set of athletes
-/// already known to this application for the credential. The owner of the
-/// credential is included naturally because the login creates that row.
-pub async fn session_accessible_athletes(
-    db: &PgPool,
-    token: &str,
-) -> Result<Vec<SessionAthlete>> {
-    let hash = hash_token(token);
-
-    let rows = sqlx::query(
-        r#"
-        SELECT DISTINCT
-            a.id,
-            a.intervals_athlete_id,
-            a.display_name,
-            a.access_token
-        FROM sessions s
-        JOIN athletes current_athlete
-          ON current_athlete.id = s.athlete_id
-        JOIN athletes a
-          ON a.access_token = current_athlete.access_token
-        WHERE s.token_hash = $1
-          AND s.created_at > now() - interval '1 day'
-        ORDER BY a.display_name, a.intervals_athlete_id
-        "#,
-    )
-    .bind(&hash)
-    .fetch_all(db)
-    .await?;
-
-    use sqlx::Row;
-
-    rows.into_iter()
-        .map(|row| {
-            Ok(SessionAthlete {
-                id: row.try_get("id")?,
-                intervals_athlete_id: row.try_get("intervals_athlete_id")?,
-                display_name: row.try_get("display_name")?,
-                access_token: row.try_get("access_token")?,
-            })
-        })
-        .collect()
-}
-
 /// Return the start time of the most recently imported activity
 /// for an athlete.
 ///