Oci layout path fix

[EladAviczer]

Fixes #2455
Description
This PR addresses issue #2455 by enhancing the functionality of the --oci-layout-path flag in kaniko. Previously, this flag only accepted absolute paths, which limited usability for users working with relative paths.
(unittests not included since i use the same tests for all other opts)
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Examples of user facing changes:
- kaniko adds relative path usage for --oci-layout-path 

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