fix(image): parse image.inspect.Created field only for non-empty values

[DmitriyLewen]

Description

Created field can be empty - https://github.com/moby/moby/blob/8e96db1c328d0467b015768e42a62c0f834970bb/api/types/types.go#L76-L77
We don't need to parse this empty field to avoid errors.

Error example - #6944

Related issues

• Close Images with deleted timestamps break with Docker 26 #6947

Checklist

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• I've added tests that prove my fix is effective or that my feature works.
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