feat(otel): add OTLPIntegration

[Litarnus]

Add proper support for the OLTPIntegration introduced in sentry-php

[sentry]

Bug: The OTLPIntegration is registered in the DI container but isn't added to the active integrations list, so it remains inactive by default.
_{Severity: MEDIUM}

Suggested Fix

Implement a method in SentryExtension.php similar to configureRequestIntegration(). This new method should add OTLPIntegration to the list of active integrations passed to the Sentry SDK, ensuring it is enabled by default as intended.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent.
Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not
valid.

Location: src/Resources/config/services.yaml#L119

Potential issue: Registering `Sentry\Integration\OTLPIntegration` in `services.yaml`
makes it available in the Symfony DI container, but does not automatically activate it
within the Sentry SDK. The logic in `SentryExtension.php` builds the list of active
integrations but lacks a mechanism to include `OTLPIntegration`, unlike
`RequestIntegration` which is handled by `configureRequestIntegration()`. As a result,
the OTLP integration will be inactive by default unless users manually add it to their
configuration, which contradicts the PR's goal of providing out-of-the-box support.

_{Did we get this right? 👍 / 👎 to inform future reviews.}

[Litarnus]

This is intentional so that it can be used but we don't want to add it by default