fix: Remove group and project variable resources from state when they are no longer found

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If a group or project variable that is managed by terraform is removed manually, it results in errors in subsequent plan/apply commands. The first time the command is run, the ID is set to the empty string. The following run, the ID cannot be validated and returns the Invalid resource ID format error. The only workaround after that point is removing the object from state manually.

Signed-off-by: Jonathan Dorsey jonathand@liatrio.com