fix(provider): reap_timeouts not firing for txs already in waiting_confs

[vanityKoa]

When a tx with with_timeout() gets included in a block but still needs more confirmations, it moves from unconfirmed to waiting_confs. The reap_at entry stays, but when the timeout fires, reap_timeouts only checks unconfirmed — the remove returns None and the timeout is silently swallowed.

Example:
user sends a tx with required_confirmations = 20 and timeout = 60s. The tx lands in a block after 5s and moves to waiting_confs. At 60s the timeout fires, but unconfirmed.remove() finds nothing, so the user never gets a Timeout error and hangs forever if confirmations stall.

Now reap_timeouts falls back to scanning waiting_confs when the tx isn't in unconfirmed.