test(eth): ensure wait_for_transaction_receipt accepts hex-string tx hash (success & timeout) (#2043)

[tomonorisasaki]

Summary
Add regression tests to ensure wait_for_transaction_receipt() accepts a transaction hash provided as a hex string, both on the success path and on the timeout path.

What this does

• Success path: pass a mined tx hash as hex string and assert a receipt is returned
• Timeout path: pass a bogus 32‑byte hex string and assert TimeExhausted is raised

Why
Historically, passing a hex string could lead to a TypeError in the timeout branch where to_hex is called. These tests ensure the current behavior remains stable.

Related Issue
Refs #2043

Notes
Happy to move/rename the test file if maintainers prefer a different location.