This terraform-plugin-sdk (v1) analyzer has been removed in tfproviderlint v0.30.0.
The V005 analyzer reports usage of the deprecated ValidateJsonString validation function that should be replaced with StringIsJSON.
ValidateFunc: validation.ValidateJsonString,
ValidateFunc: validation.StringIsJSON,
Singular reports can be ignored by adding the a //lintignore:V005
Go code comment at the end of the offending line or on the line immediately proceding, e.g.
//lintignore:V005
ValidateFunc: validation.ValidateJsonString,