Fix Pipenv graph invalid JSON

[attiasas]

• All tests passed. If this feature is not already covered by the tests, I added new tests.
• All static analysis checks passed.
• This pull request is on the dev branch.
• I used gofmt for formatting the code before submitting the pull request.

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Fix (Also add extend logs for debugging)

For some projects pipenv graph --json produce not valid json (added \n) prevents Unmarshal

Error: 3 [Error] target '/tmp/jfrog.cli.temp.-1734955979-676905686 [pipenv]' errors:
Failed to build dependency tree: failed while building 'pipenv' dependency tree: failed to parse pipenv graph --json output: invalid character '\n' in string literal

[github-actions]

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