refactor(block): use icon value as key instead of class for consisten…

…cy (#9689)

**Related Issue:** N/A

## Summary

✨🧹✨

packages/calcite-components/src/components/block/block.tsx

@@ -403,7 +403,7 @@ export class Block
         class={iconClass}
         flipRtl={flipRtl}
         icon={iconValue}
-        key={iconClass}
+        key={iconValue}
         scale="s"
       />
     );