Fix typo in unstable_cache.mdx (vercel#62301)

docs/02-app/02-api-reference/04-functions/unstable_cache.mdx

@@ -21,7 +21,7 @@ export default async function Component({ userID }) {
 ```
 
 > **Good to know**:
-> Accessing dynamic data sources such as `headers` or `cookies` inside a cache scope is not supported. If you need this data inside a cached function use `headers` oustide of the cached function and pass the required dynamic data in as an argument.
+> Accessing dynamic data sources such as `headers` or `cookies` inside a cache scope is not supported. If you need this data inside a cached function use `headers` outside of the cached function and pass the required dynamic data in as an argument.
 
 > **Warning**: This API is unstable and may change in the future. We will provide migration documentation and codemods, if needed, as this API stabilizes.