[Stack 8.19.19-SNAPSHOT] [oracle] Failing test daily: system test: (elastic-agent logs - systemstatistics) in oracle.system_statistics

- Stack version: 8.19.19-SNAPSHOT
- Package: oracle
- Failing test: system test: (elastic-agent logs - systemstatistics)
- DataStream: system_statistics
- Owners:
- @elastic/obs-infraobs-integrations

Failure:
```
test case failed: one or more errors found while examining elastic-agent.logs2583981185: [0] found error "Unit state changed sql/metrics-default-sql/metrics-oracle-aec62407-2409-46ca-b6f2-14e177108ac6 (HEALTHY->DEGRADED): Error fetching data for metricset sql.query: cannot open connection: testing connection: user=\"sys\" standalone params={authMode:2 connectionClass: connectionClassLength:0 purity:0 newPassword: newPasswordLength:0 appContext: numAppContext:0 externalAuth:0 externalHandle: pool: tag: tagLength:0 matchAnyTag:0 outTag: outTagLength:0 outTagFound:0 shardingKeyColumns: numShardingKeyColumns:0 superShardingKeyColumns: numSuperShardingKeyColumns:0 outNewSession:0}: ORA-12541: TNS:no listener"
```

First build failed: https://buildkite.com/elastic/integrations/builds/46081

Latest 5 failed builds:
- https://buildkite.com/elastic/integrations/builds/46710
- https://buildkite.com/elastic/integrations/builds/46801
- https://buildkite.com/elastic/integrations/builds/46859
- https://buildkite.com/elastic/integrations/builds/46920
- https://buildkite.com/elastic/integrations/builds/47003

Start with the latest failed Buildkite runs and the elastic-agent logs for the oracle.system_statistics data stream, focusing on the ORA-12541 no-listener failure. Determine whether the failure is in the Oracle test setup or integration, then make the daily system test complete without the degraded sql.query metricset.

Written by the indexing model from the issue text.