chore: remove unnecessary eslint-disable directive (#7283)

Co-authored-by: Jay <jasonsaayman@gmail.com>

lib/core/mergeConfig.js

@@ -30,7 +30,6 @@ export default function mergeConfig(config1, config2) {
     return source;
   }
 
-  // eslint-disable-next-line consistent-return
   function mergeDeepProperties(a, b, prop, caseless) {
     if (!utils.isUndefined(b)) {
       return getMergedValue(a, b, prop, caseless);