Fix OpenTelemetry Metrics and Logs endpoint resolution

[gsmet]

Fixes #46351

@brunobat I'm not entirely sure if we can easily add tests for it?

[quarkus-bot]

/cc @brunobat (opentelemetry), @radcortez (opentelemetry)

[brunobat]

Let me have a look

[brunobat]

Looks like I implemented the metrics endpoint resolver, created unit tests for it and forgot to actually use it.🙄
The Logs one is just a copy/paste error.
Manually testing this for now.

[quarkus-bot]

Status for workflow Quarkus CI

This is the status report for running Quarkus CI on commit 19f2ec6.

✅ 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

⚙️ Native Tests - HTTP

📦 integration-tests/rest-client-reactive

✖ io.quarkus.it.rest.client.BasicTestIT.shouldCreateClientSpans - History

• expected: <1> but was: <2> - org.opentest4j.AssertionFailedError

org.opentest4j.AssertionFailedError: expected: <1> but was: <2>
	at io.quarkus.it.rest.client.BasicTest.shouldCreateClientSpans(BasicTest.java:216)
	at java.base/java.lang.reflect.Method.invoke(Method.java:569)
	at io.quarkus.test.junit.QuarkusTestExtension.interceptTestMethod(QuarkusTestExtension.java:799)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)

[brunobat]

Manually tested.
Tried Wiremock but got nowhere as the payloads are protobuf and Wiremock doesn't seem to detect the calls.
The IT test setup is complex with test containers but will give it a try in the future. I think we can merge this for now.