feat: add get_ref to retrieve Resource values by reference

opentelemetry-sdk/CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## vNext
 
+### Added
+- Added `Resource::get_ref(&self, key: &Key) -> Option<&Value>` to allow retrieving a reference to a resource value without cloning.
+
 ## 0.31.0
 
 Released 2025-Sep-25

opentelemetry-sdk/src/resource/mod.rs

@@ -228,6 +228,11 @@ impl Resource {
     pub fn get(&self, key: &Key) -> Option<Value> {
         self.inner.attrs.get(key).cloned()
     }
+
+    /// Returns a reference to the value for the resource associated with the given key without cloning.
+    pub fn get_ref(&self, key: &Key) -> Option<&Value> {
+        self.inner.attrs.get(key)
+    }
 }
 
 /// An iterator over the entries of a `Resource`.