Add debug spans for new_revision and evict_lru

Author: Veykril

src/zalsa.rs

@@ -355,6 +355,7 @@ impl Zalsa {
     #[doc(hidden)]
     pub fn new_revision(&mut self) -> Revision {
         let new_revision = self.runtime.new_revision();
+        let _span = tracing::debug_span!("new_revision", ?new_revision).entered();
 
         for (_, index) in self.ingredients_requiring_reset.iter() {
             let index = index.as_usize();
@@ -372,6 +373,7 @@ impl Zalsa {
     /// **NOT SEMVER STABLE**
     #[doc(hidden)]
     pub fn evict_lru(&mut self) {
+        let _span = tracing::debug_span!("evict_lru").entered();
         for (_, index) in self.ingredients_requiring_reset.iter() {
             let index = index.as_usize();
             self.ingredients_vec