Important Breaking Changes
Once your Dynatrace Environment has gotten (auto)-updated to v1.280 applying the resources dynatrace_span_attribute and dynatrace_resource_attributes will result with an error message signalling that the old schemata are not valid anymore.
At this point you will have to migrate your modules to use the resources dynatrace_attribute_allow_list and dynatrace_attribute_masking.
Reason for that is a breaking change in the REST API with cluster version 1.280 scheduled to be released in a few days. While we were able to implement an adapter for the resource dynatrace_span_attribute (kudos to @kishikawa12), implementing something similar for dynatrace_resource_attributes unfortunately turned out to be too complex.