PR description

I’ve made a few updates to the script to improve its efficiency and readability, as well as fix some minor issues. Here's a breakdown of what’s been changed:

• Architecture Detection: I added a line to automatically detect the system architecture (export architecture=$(uname -m)), which helps if the architecture variable isn't provided earlier.

• Modern Syntax for Incrementing: Replaced the outdated syntax (i=\expr $i + 1) with the more modern ((i++)). This not only improves readability but also enhances the script’s performance.

• Grammar Fix: I corrected a grammatical issue in the comments by updating the line:

  # we test that things listen on the right interface/port, not what interface they advertise

• Replacing Inefficient Constructs: Switched the use of expr to ((i++)) for numerical operations, which is more efficient in Bash.

• Error Checking Improvements: Changed [[ $i != 0 ]] to ((i != 0)) for checking the value of i, as the latter is more appropriate and standard for numeric comparisons in Bash.

• Directory Creation: Added a step to ensure that the necessary report directories exist (mkdir -p ./reports) or created them if they were missing. This prevents errors when generating reports.

These updates should make the script more stable, modern, and easier to work with.

Thanks for sending a pull request! Have you done the following?

• Checked out our contribution guidelines?
• Considered documentation and added the doc-change-required label to this PR if updates are required.
• Considered the changelog and included an update if required.
• For database changes (e.g. KeyValueSegmentIdentifier) considered compatibility and performed forwards and backwards compatibility tests

Locally, you can run these tests to catch failures early:

• unit tests: ./gradlew build
• acceptance tests: ./gradlew acceptanceTest
• integration tests: ./gradlew integrationTest
• reference tests: ./gradlew ethereum:referenceTests:referenceTests