Fix docker compose warning regarding the version field

[XSAM]

Fix this warning:

WARN[0000] otelsql/example/otel-collector/docker-compose.yaml: `version` is obsolete

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 84.1%. Comparing base (2e34895) to head (81c68de).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #255 +/- ## ===================================== Coverage 84.1% 84.1% ===================================== Files 13 13 Lines 605 605 ===================================== Hits 509 509 Misses 72 72 Partials 24 24 ```

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