[Task]: Remove leftover traces of pubsublite deprecation

### What needs to happen?

#37375 removed all code using pubsublite and thus accomplishing the goal of deprecation. This task should NOT be a release blocker.

This task is to clean up any remaining documentation etc of any traces of pubsublite. This task is to make it squeaky clean.

https://github.com/search?q=repo%3Aapache%2Fbeam%20pubsublite&type=code
As of 2026-02-02:

- [x] 1. [website/www/site/content/en/documentation/io/connectors.md] - Will be fixed after 2.72 release complete and website is updated - just verify.
- [ ] 2. [infra/iam/roles/roles_config.yaml] - remove comment. - wait until after June 30th - https://docs.cloud.google.com/pubsub/lite/docs - https://github.com/apache/beam/pull/39237
- [ ] 3. [website/www/site/content/en/documentation/dsls/sql/extensions/create-external-table.md] - Will be fixed after 2.72 release complete and website is updated - just verify - https://github.com/apache/beam/pull/39237
- [x] 4. [examples/notebooks/get-started/try-apache-beam-yaml.ipynb] - opened PR #37457
- [ ] 5. [playground/frontend/playground_components/assets/symbols/java.g.yaml] - I tried multiple times trying to update the symbols etc, but playground frontend test seems like in a permared situation. Flutter is on 3.10.4 while there are much newer versions. So dependency issues etc. See #37461 for initial work. I can get everything working through commit checks, but integration tests fail with multiple differerent errors due to maybe race conditions or analysis events not finishing. This should be a separate task to fix playground test which will take care of the pubsitelite symbols being removed during the process. Should be fixed when https://github.com/apache/beam/issues/37478 is fixed.
- [ ] 6. [playground/frontend/playground_components/assets/symbols/python.g.yaml] - same as above.

### Issue Priority

Priority: 2 (default / most normal work should be filed as P2)

### Issue Components

- [ ] Component: Python SDK
- [ ] Component: Java SDK
- [ ] Component: Go SDK
- [ ] Component: Typescript SDK
- [ ] Component: IO connector
- [ ] Component: Beam YAML
- [x] Component: Beam examples
- [x] Component: Beam playground
- [ ] Component: Beam katas
- [x] Component: Website
- [x] Component: Infrastructure
- [ ] Component: Spark Runner
- [ ] Component: Flink Runner
- [ ] Component: Samza Runner
- [ ] Component: Twister2 Runner
- [ ] Component: Hazelcast Jet Runner
- [ ] Component: Google Cloud Dataflow Runner