Add retry logic with exponential backoff to zombienet SDK tests

[DenzelPenzel]

Description

Add retry logic with exponential backoff to zombienet SDK tests #10583

This commit adds configurable retry logic to the zombienet-sdk GitHub action to handle infra test issues.

Key changes include:

• Add max-retries and initial-delay-seconds input parameters to the action (defaults: 3 retries, 10s initial delay)
• Implement exponential backoff retry logic in test execution with grouped output for each attempt
• Increase log processing sleep time from 60s to 240s to allow more time for log forwarding

Example of retrying the test https://github.com/paritytech/polkadot-sdk/actions/runs/20070112519/job/57571339539?pr=10584

[pepoviola]

Hey @DenzelPenzel, looks good but most of the infra issues in the tests are downloading the artifacts we need to make the retry logic there too.

[DenzelPenzel]

Implemented retry logic for artifact downloads in the zombienet CI infra #10588
cc @pepoviola