[JENKINS-76320] Add support for `withIndex(int offset)`

[jenkins-infra-bot]

I know I can do `withIndexEach`, but it always starts from 0, and humans count from 1...

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Originally reported by victor_yousician, imported from: Add support for `withIndex(int offset)`

• status: Open
• priority: Minor
• component(s): workflow-cps-plugin
• resolution: Unresolved
• votes: 0
• watchers: 1
• imported: 2025-12-07

Raw content of original issue

I know I can do `withIndexEach`, but it always starts from 0, and humans count from 1...