Fix: Add util helper function to resolve ring topography ci checks failure

[yashksaini-coder]

Issue #1164

How was it fixed?

What I changed in your original function #1164 (comment)

In wait_for_convergence():

Added tracking of the last exception

• New locals: last_exception, last_exception_node
• Whenever check(node) raises, we store the exception and node index.
• Added raise_last_exception_on_timeout (default True)

On timeout, if we saw an exception during checks, we now raise:
AssertionError("Convergence failed (node index X): ") from
This keeps the real assertion failure visible (and chained), instead of masking it behind TimeoutError.

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[yashksaini-coder]

@seetadev The PR, is ready for review and final merge to resolve failing gossipsub checks. A detailed discussion page is present here, #1166