- removes unused context functions from test context fixtures

[#3]

…l stamp tests

…ion on workflow_dispatch

…rting.'

…for production/staging

- removes unused context functions from test context fixtures

[#3]

…l stamp tests

[#3]

Previously, the IAM tests were relying on on-chain data and, therefore, needed the RPC_URL to run
tests.
 Since we don't rely on on-chain data anymore, we can remove the environment variable from
the test step.

 This also fixes the poh implementation to use the RPC_URL env variable instead of
being hard-coded to the mainnet variable. This matches the convention we are using elsewhere (ENS,
etc).

[#3]