Enable clippy::search_is_some (#8748)

This PR enables the
[`clippy::search_is_some`](https://rust-lang.github.io/rust-clippy/master/index.html#/search_is_some)
rule and fixes the outstanding violations.

Release Notes:

- N/A

crates/feature_flags/src/feature_flags.rs

@@ -8,7 +8,7 @@ struct FeatureFlags {
 
 impl FeatureFlags {
     fn has_flag(&self, flag: &str) -> bool {
-        self.staff || self.flags.iter().find(|f| f.as_str() == flag).is_some()
+        self.staff || self.flags.iter().any(|f| f.as_str() == flag)
     }
 }