Ignore serverComponentChanges in pages (#41464)

Slightly different version of #41020 where it does not end up being an unknown event.



## Bug

- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have a helpful link attached, see `contributing.md`

## Feature

- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have a helpful link attached, see `contributing.md`

## Documentation / Examples

- [ ] Make sure the linting passes by running `pnpm lint`
- [ ] The "examples guidelines" are followed from [our contributing doc](https://github.com/vercel/next.js/blob/canary/contributing/examples/adding-examples.md)

packages/next/client/dev/error-overlay/hot-dev-client.js

@@ -260,6 +260,10 @@ function processMessage(e) {
       )
       return handleSuccess()
     }
+    case 'serverComponentChanges': {
+      // Server component changes don't apply to `pages`.
+      return
+    }
     default: {
       if (customHmrEventHandler) {
         customHmrEventHandler(obj)