[Stack 8.19.20-SNAPSHOT] [oracle] Failing test daily: system test: (elastic-agent logs - sysmetric) in oracle.sysmetric

- Stack version: 8.19.20-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.logs1558925006: [0] found error "Unit state changed sql/metrics-default-sql/metrics-oracle-c1829fe9-3744-4e15-946a-296e3707a52e (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/47075

Latest 5 failed builds:
- https://buildkite.com/elastic/integrations/builds/48319
- https://buildkite.com/elastic/integrations/builds/48398
- https://buildkite.com/elastic/integrations/builds/48455
- https://buildkite.com/elastic/integrations/builds/48532
- https://buildkite.com/elastic/integrations/builds/48614

Start by reviewing the failing Oracle sysmetric system test and the linked Buildkite failures, beginning with build 47075 and comparing the five later failed builds. Trace the elastic-agent logs error showing ORA-12541 and determine whether the listener failure is in the test environment or integration setup. Done means the sysmetric test passes reliably in the Oracle system test runs.

Written by the indexing model from the issue text.