Enable the unicorn/prefer-optional-catch-binding ESLint plugin rule

According to MDN this format is available in all browsers/environments that we currently support, see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/try...catch#browser_compatibility

Please also see https://github.com/sindresorhus/eslint-plugin-unicorn/blob/main/docs/rules/prefer-optional-catch-binding.md

src/core/dataset_reader.js

@@ -53,7 +53,7 @@ class DatasetReader {
       const parser = new DatasetXMLParser({ hasAttributes: true });
       try {
         parser.parseFromString(data["xdp:xdp"]);
-      } catch (_) {}
+      } catch {}
       this.node = parser.node;
     }
   }