docs(tracer): add callout about ADOT

[dreamorosi]

Description of your changes

As discussed with other maintainers, after hearing customer feedback we have decided to add a callout to the Tracer documentation to explain why we use X-Ray over ADOT/OTEL.

This PR introduces the banner shown in the screenshot below:

Related issues, RFCs

Issue number: #1580

Checklist

• My changes meet the tenets criteria
• I have performed a self-review of my own code
• I have commented my code where necessary, particularly in areas that should be flagged with a TODO, or hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my change is effective and works
• The PR title follows the conventional commit semantics

Breaking change checklist

Is it a breaking change?: NO

• I have documented the migration process
• I have added, implemented necessary warnings (if it can live side by side)

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