upgrade(deps): bump minimum ddtrace version to v2.20.0

[mabdinur]

What does this PR do?

• Upgrades ddtrace to v2.20.0
• Ensures tracing attributes are imported from the new ddtrace.trace package.

Motivation

References to ddtrace.Span, ddtrace.Pin, and ddtrace.Tracer were deprecated in v2.20.0 and will be removed in 3.0. Moving forward tracing attributes must be imported from the ddtrace.trace package.

Testing Guidelines

Additional Notes

Types of Changes

• Bug fix
• New feature
• Breaking change
• Misc (docs, refactoring, dependency upgrade, etc.)

Check all that apply

• This PR's description is comprehensive
• This PR contains breaking changes that are documented in the description
• This PR introduces new APIs or parameters that are documented and unlikely to change in the foreseeable future
• This PR impacts documentation, and it has been updated (or a ticket has been logged)
• This PR's changes are covered by the automated tests
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[mabdinur]

Blocked by: #544