various: auto-fix clippy warnings

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: Ia8f0b1ebd657bb9cdebef9d62413f45a6a6a6964

crates/db/src/lib.rs

@@ -32,6 +32,7 @@ pub struct RouteEntry {
 }
 
 impl RouteEntry {
+  #[must_use] 
   pub fn is_valid(&self) -> bool {
     Utc::now() < self.ttl
   }

crates/health/src/lib.rs

@@ -16,6 +16,7 @@ pub enum Status {
 }
 
 impl Status {
+  #[must_use] 
   pub const fn as_str(self) -> &'static str {
     match self {
       Self::Active => "ACTIVE",
@@ -65,6 +66,7 @@ struct ProberInner {
 }
 
 impl Prober {
+  #[must_use] 
   pub fn new(alpha: f64) -> Self {
     Self {
       inner: Arc::new(ProberInner {

crates/mesh/src/lib.rs

@@ -72,9 +72,11 @@ impl Node {
     })
   }
 
+  #[must_use] 
   pub fn id(&self) -> String {
     hex::encode(&self.public_key()[..8])
   }
+  #[must_use] 
   pub fn public_key(&self) -> [u8; 32] {
     self.signing_key.verifying_key().to_bytes()
   }

crates/metrics/src/lib.rs

@@ -99,6 +99,7 @@ pub fn get() -> &'static Metrics {
   })
 }
 
+#[must_use] 
 pub fn gather() -> String {
   let mut buf = Vec::new();
   let encoder = TextEncoder::new();

crates/narinfo/src/lib.rs

@@ -164,6 +164,7 @@ impl NarInfo {
     Ok(narinfo)
   }
 
+  #[must_use] 
   pub fn fingerprint(&self) -> String {
     let refs = self
       .references

crates/router/src/lib.rs

@@ -57,6 +57,7 @@ struct RaceResult {
 }
 
 impl Router {
+  #[must_use] 
   pub fn new(
     db: Db,
     prober: Prober,