chore: Update JSDoc return types for clarity in MetricGraph and Metric

- Changed return type in MetricGraph's JSDoc from Components.Data.Metric to MetricGraph for better accuracy.
- Updated return type in Metric's JSDoc from Components.Data.Metric to Metric to ensure consistency and clarity.

These changes improve documentation accuracy, making it clear what these methods return, which helps maintainers understand the codebase better.

source/components/data/metric-graph.mjs

@@ -60,7 +60,7 @@ class MetricGraph extends CustomElement {
 	}
 
 	/**
-	 * @return {Components.Data.Metric
+	 * @return {MetricGraph}
 	 */
 	[assembleMethodSymbol]() {
 		super[assembleMethodSymbol]();

source/components/data/metric.mjs

@@ -56,7 +56,7 @@ class Metric extends CustomElement {
 	}
 
 	/**
-	 * @return {Components.Data.Metric
+	 * @return {Metric}
 	 */
 	[assembleMethodSymbol]() {
 		super[assembleMethodSymbol]();