docs: Add eslint-config-turbo bump to uprade guide. (#9391)

### Description

We were missing the guidance to make sure that ESLint got upgraded. This
fixes it!

### Testing Instructions

👀

docs/repo-docs/crafting-your-repository/upgrading.mdx

@@ -95,6 +95,13 @@ Turborepo 2.0 requires that your Workspace define this field as a way to improve
 </Tab>
 </PackageManagerTabs>
 
+</Step>
+<Step>
+
+### Update `eslint-config-turbo`
+
+[`eslint-config-turbo`](/repo/docs/reference/eslint-config-turbo) helps identify environment variables that need to be added to the [`env`](/repo/docs/reference/configuration#env) key for caching. If you're using it, make sure you update it to match your major version.
+
 </Step>
 
 <Step>