Update datasource observability configs docs and setup

[brunobat]

Relates with #22556

The documentation for quarkus.datasource.jdbc.enable-metrics is outdated. Prop should be deprecated because it's related with quarkus-smallrye-metrics but we cannot remove it for now.

The PR also includes a setup simplification for tracing.

[quarkus-bot]

/cc @radcortez (opentelemetry)

[quarkus-bot]

Status for workflow Quarkus Documentation CI

This is the status report for running Quarkus Documentation CI on commit a9ddc59.

✅ The latest workflow run for the pull request has completed successfully.

It should be safe to merge provided you have a look at the other checks in the summary.

Warning

There are other workflow runs running, you probably need to wait for their status before merging.

[github-actions]

🙈 The PR is closed and the preview is expired.

[quarkus-bot]

Status for workflow Quarkus CI

This is the status report for running Quarkus CI on commit a9ddc59.

✅ The latest workflow run for the pull request has completed successfully.

It should be safe to merge provided you have a look at the other checks in the summary.

You can consult the Develocity build scans.

---

Flaky tests - Develocity

⚙️ JVM Integration Tests - JDK 21

📦 integration-tests/opentelemetry

✖ io.quarkus.it.opentelemetry.LoggingResourceTest.testException - History

• Condition with Lambda expression in io.quarkus.it.opentelemetry.LoggingResourceTest was not fulfilled within 2 minutes. - org.awaitility.core.ConditionTimeoutException

org.awaitility.core.ConditionTimeoutException: Condition with Lambda expression in io.quarkus.it.opentelemetry.LoggingResourceTest was not fulfilled within 2 minutes.
	at org.awaitility.core.ConditionAwaiter.await(ConditionAwaiter.java:167)
	at org.awaitility.core.CallableCondition.await(CallableCondition.java:78)
	at org.awaitility.core.CallableCondition.await(CallableCondition.java:26)
	at org.awaitility.core.ConditionFactory.until(ConditionFactory.java:1160)
	at org.awaitility.core.ConditionFactory.until(ConditionFactory.java:1129)
	at io.quarkus.it.opentelemetry.LoggingResourceTest.testException(LoggingResourceTest.java:113)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)