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

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

Failure:
```
test case failed: one or more errors found while examining elastic-agent.logs4188777841: [0] found error "Unit state changed sql/metrics-default-sql/metrics-oracle-a4334a66-a54e-4409-93bb-b341e1d848f9 (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/46082

Latest 5 failed builds:
- https://buildkite.com/elastic/integrations/builds/46709
- https://buildkite.com/elastic/integrations/builds/46802
- https://buildkite.com/elastic/integrations/builds/46860
- https://buildkite.com/elastic/integrations/builds/46919
- https://buildkite.com/elastic/integrations/builds/47004

Review the oracle.memory system test failure in the linked Buildkite runs, starting with the ORA-12541 “TNS:no listener” error and comparing the repeated failures. The issue is resolved when the elastic-agent logs memory test passes in the Oracle integration builds without the listener error.

Written by the indexing model from the issue text.