community: chore warn deprecate the tracer (#27159)
- **Description:**: This PR deprecates the wandb tracer in favor of the
new
[WeaveTracer](https://weave-docs.wandb.ai/guides/integrations/langchain#using-weavetracer)
in W&B
- **Dependencies:** No dependencies, just a deprecation warning.
- **Twitter handle:** @parambharat
@baskaryan
