[Stack 8.19.21-SNAPSHOT] [oracle] Failing test daily: system test: (elastic-agent logs - performance) in oracle.performance

- Stack version: 8.19.21-SNAPSHOT
- Package: oracle
- Failing test: system test: (elastic-agent logs - performance)
- DataStream: performance
- Owners:
- @elastic/obs-infraobs-integrations

Failure:
```
test case failed: one or more errors found while examining elastic-agent.logs1191582234: [0] found error "Unit state changed sql/metrics-default-sql/metrics-oracle-4d9715e4-e889-4a4c-825a-1a6cbadce026 (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/49027

Latest failed builds:
- https://buildkite.com/elastic/integrations/builds/49093
- https://buildkite.com/elastic/integrations/builds/49169
- https://buildkite.com/elastic/integrations/builds/49242
- https://buildkite.com/elastic/integrations/builds/49336

Start with the oracle package's system test for the elastic-agent logs performance data stream and review the linked failed Buildkite builds. Investigate the ORA-12541 no-listener failure affecting the sql.query metricset; done means the test passes reliably in subsequent builds without the degraded unit state.

Written by the indexing model from the issue text.