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

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

Failure:
```
test case failed: one or more errors found while examining elastic-agent.logs2871195465: [0] found error "Unit state changed sql/metrics-default-sql/metrics-oracle-aa3e54cf-6eda-4e44-bd6f-d361bfdd3ccc (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/49028

Latest failed builds:
- https://buildkite.com/elastic/integrations/builds/49092
- https://buildkite.com/elastic/integrations/builds/49170
- https://buildkite.com/elastic/integrations/builds/49243
- https://buildkite.com/elastic/integrations/builds/49335

Start by reproducing the failing oracle.tablespace system test for the elastic-agent logs tablespace data stream and review the linked Buildkite failures. Investigate the ORA-12541 “TNS:no listener” connection error; done means the test passes reliably against the Oracle setup.

Written by the indexing model from the issue text.