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

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

Failure:
```
test case failed: one or more errors found while examining elastic-agent.logs2457378104: [0] found error "Unit state changed sql/metrics-default-sql/metrics-oracle-ca7e8e96-ee27-45b8-aa36-f5422f1d92a2 (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 failing Oracle sysmetric system test and inspect the elastic-agent logs output for the sql.query connection error. Compare the first and latest Buildkite failures, then determine whether the ORA-12541 listener failure is reproducible; done means the sysmetric test completes without the connection error.

Written by the indexing model from the issue text.