Fix lint errors (#281)

buildpacks/ruby/src/gem_list.rs

@@ -80,7 +80,7 @@ impl GemList {
 
     #[must_use]
     pub(crate) fn has(&self, str: &str) -> bool {
-        self.gems.get(&str.trim().to_lowercase()).is_some()
+        self.gems.contains_key(&str.trim().to_lowercase())
     }
 }
 

buildpacks/ruby/src/layers/bundle_install_layer.rs

@@ -210,10 +210,10 @@ impl Layer for BundleInstallLayer<'_> {
 enum Changed {
     Nothing,
 
-    /// The stack changed i.e. from heroku_20 to heroku_22
+    /// The stack changed i.e. from `heroku-20` to `heroku-22`
     /// When that happens we must invalidate native dependency gems
     /// because they're compiled against system dependencies
-    /// i.e. https://devcenter.heroku.com/articles/stack-packages
+    /// i.e. <https://devcenter.heroku.com/articles/stack-packages>
     /// TODO: Only clear native dependencies instead of the whole cache
     Stack(StackId, StackId), // (old, now)
 

commons/src/output/warn_later.rs

@@ -206,11 +206,11 @@ where
 {
     // Private inner to force public construction through `new()` which tracks creation state per thread.
     io: W,
-    /// The use of WarnGuard is directly tied to the thread where it was created
+    /// The use of `WarnGuard` is directly tied to the thread where it was created
     /// This forces the struct to not be send or sync
     ///
     /// To move warn later data between threads, drain quietly, send the data to another
-    /// thread, and re-apply those warnings to a WarnGuard in the other thread.
+    /// thread, and re-apply those warnings to a `WarnGuard` in the other thread.
     unsync: PhantomUnsync,
 }