Add logfire support

[Undertone0809]

Checked

• I searched existing ideas and did not find a similar one
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• I've clearly described the feature request and motivation for it

Feature request

From the team behind Pydantic, Logfire is a new type of observability platform built on the same belief as our open source library — that the most powerful tools can be easy to use.

Official website: https://pydantic.dev/

Motivation

Integrating Logfire makes it easier to trace the entire python system.

Proposal (If applicable)

No response

[Avo-k]

that would be very nice, but as langchain is selling langsmith and logfire is a good "free" alternative, I doubt they implement it