Go SDK: declare data edges with airflow.Inputs - #73895

Implement Go SDK: Declare data edges with airflow.Inputs.

• airflow.Inputs(refs...) is a TaskOption. dag.Task records the tasks in the order of the parameters after airflow.Context, and each of them becomes an upstream task of the new task.
• dag.Task checks the inputs when it adds a task. It panics in these cases, with a message that names the new task and any upstream task involved:
  • The number of tasks in Inputs does not match the number of parameters after airflow.Context. A task that has parameters but no Inputs counts as a mismatch.
  • An upstream task's result type cannot be assigned to the parameter it fills, by the same rule as a Go function call. For example, a *T result does not fit a T parameter.
  • An upstream task returns only an error, so it has no result to pass.
  • An upstream task belongs to another Dag.
  • The same task gets a second Inputs.

Was generative AI tooling used to co-author this PR?

• Yes - Claude Code

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