Improves on try_recv in e2e tests

[grarco]

About the mpsc channel read loop in e2e tests

namada/crates/tests/src/e2e/setup.rs

Line 899 in 45e7e90

match abort_recv.try_recv() {

          unrelated to this PR, but this `try_recv` might be contributing substantially to the resource usage of e2e tests :P

Originally posted by @sug0 in #3894 (comment)

Seems like the solution is to call recv_timeout instead with a sane timeout

[grarco]

I've actually tried to implement this and the tests started to fail. Specifically they fail in exp_regex on a Hermes NamadaCmd because of a timeout on the output stream when creating the IBC channel (create_channel_ibc_with_hermes). This does not depend on the specific timeout we set neither in recv_timeout nor in the Session. It could be due to the Session instances of Namada and Gaia controlling the streams of their processes: being blocked would prevent them from replying to the Hermes requests