CloudFormation Specifications
- Update CloudFormation specs to `91.0.0` (pull [2392](https://github.com/aws-cloudformation/cfn-lint/pull/2392))
Fixes
- Update [E8003](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E8003), [E1018](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E1018), [E1019](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E1019) to allow `Fn::ToJsonString` inside `Equals`, `Split`, and `Sub` (pull [2397](https://github.com/aws-cloudformation/cfn-lint/pull/2397))
- Update [I3013](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#I3013) to allow https and s3 (pull [2394](https://github.com/aws-cloudformation/cfn-lint/pull/2394))