There are several ways to exclude these libraries.
At the highest level, you can exclude them during assembly or analysis, and then there will be no results for them in the user interface, unfortunately, this also means that you will not get a complete picture of your own error in your own code, since the analysis conducts interprocedural analysis of various interactions.
So, instead, you can do something simpler. Analyze all the code, including all libraries, etc., But then configure the components in the user interface and create permissions for the components corresponding to the source of the "third party" so that users can see the source code (and you can go to it), but do not see defects. This allows you to get complete information in the user interface for developers who process defects in their own code, without being distracted by the flaws of the code in which they have no control.