chore(tests): restore parameter in e2eUtils

[dreamorosi]

Description of your changes

As documented in the linked issue, when adding the integration tests to the Idempotency utility we mistakenly introduced a bug in the e2eUtils module that caused the invocation payload to be discarded when invoking the functions deployed as part of the integration test sequentially.

This PR fixes the issue by tweaking the function to support both sequential and parallel invocations. Once merged the PR will close #1488.

Related issues, RFCs

Issue number: #1488

Checklist

• My changes meet the tenets criteria
• I have performed a self-review of my own code
• I have commented my code where necessary, particularly in areas that should be flagged with a TODO, or hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my change is effective and works
• The PR title follows the conventional commit semantics

Breaking change checklist

Is it a breaking change?: NO

• I have documented the migration process
• I have added, implemented necessary warnings (if it can live side by side)

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[dreamorosi]

Merging after confirming the fix, see successful run here.