docs(examples): use latest v2 of supabase-js and remove lock files (#44704)

* Use latest 2.x version of `@supabase/supabase-js` in all examples
* Use `latest` version of `@supabase/ssr` in all examples
* Remove lock files from examples
* Add examples lock files in .gitignore

The rationale is:
- Lock files are not actively maintained/updated (or the versions in the
package.json files for that matter)
- They pin an arbitrary version (from the end-user perspective)
- Removes the need to manually update the versions and reinstall
- Consistency

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

## Release Notes

* **Chores**
* Broadened Supabase SDK dependency version constraints across example
projects for greater flexibility with compatible updates
  * Updated some SSR package dependencies to track latest releases
* Added gitignore rules for dependency lock files in example directories

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

.gitignore

@@ -161,3 +161,8 @@ keys.json
 
 # Application
 **/.superset/**
+
+# examples
+examples/**/package-lock.json
+examples/**/yarn.lock
+examples/**/pnpm-lock.yaml