Setup conflict checks for variable secret/non-secret attributes in VG

[AlexPykavy]

To throw an error if the value attribute is used when secret was expected, and vice versa.

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What about the current behavior has changed?

Issue Number:

Does this introduce a change to go.mod, go.sum or vendor/?

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• No

Does this introduce a breaking change?

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• No

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Other information

[xuzhang3]

value, secret_value, is_secret all have default values, the constraint will always be valid, internal check will always failed

[AlexPykavy]

You are absolutely right. Moreover, referencing objects in the Set is not supported in ConflictsWith at the moment. I have another idea how to achieve this but it will be more dangerous and deserves a new PR.