docs(Migration): loaders → use (webpack#6373)

* docs(Migration): `loaders` → `use`

My understanding is that the deprecated `loaders` was removed in webpack/webpack#9138 which was in https://github.com/webpack/webpack/releases/tag/v5.74.0 (should that have been a major version upgrade?)

* Update src/content/migrate/5.mdx

Co-authored-by: Sam Chen <[email protected]>

Author: julienw

src/content/migrate/5.mdx

@@ -68,6 +68,7 @@ Update the following options to their new version (if used):
 - `Compilation.entries` → `Compilation.entryDependencies`
 - `serve` → `serve` is removed in favor of [`DevServer`](/configuration/dev-server/)
 - [`Rule.query`](/configuration/module/#ruleoptions--rulequery) (deprecated since v3) → `Rule.options`/`UseEntry.options`
+- `Rule.loaders` → [`Rule.use`](/configuration/module/#ruleuse)
 
 ### Test webpack 5 compatibility