fix: problem getting the sampling priority

[joeyzhao2018]

TICKET: https://datadoghq.atlassian.net/browse/APMSVLS-135

Background/Motivation

datadog-lambda-go uses dd-trace-go as a dependency. In the release we set dependency dd-trace-go version as 1.72.1 but customers can freely use 1.73.x or 1.74.x etc.
In dd-trace-go 1.74.x, it acts as a shim wrapper to use dd-trace-go v2. And the SpanContext is actually stored in the adapter.

datadog-lambda-go by default uses a feature called Universal Instrumentation. In short, at the beginning of a lambda invocation, it sends the event payload to the agent (extension) and let the agent create the root span. At the end of the invocation, it sends another request with the data about the span created using dd-trace-go back to the agent.

Among the data is the Sampling Priority, which is not accessible directly if the customer uses v1.74.x because it need to get the adapter first.

What does this PR do?

• This PR adds a logic that if SamplingPriority() failed, try get the sampling priority from the adapter.
• Add error logging for cases when we fail to get the Sampling Priority. Because this could impact billing directly.
• Update dd-trace-go from 1.72.1 to 1.73.1 (the last v1 that doesn't use v2)
• Update go to 1.24 from 1.23

Testing Guidelines

• Added unittests
• Tested with a real lambda using 1.74.3

Additional Notes

Types of changes

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

Checklist

• 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
• This PR collects user input/sensitive content into Datadog