In short, there are areas of law where if the Federal scope includes that subject matter, the state loses power to legislate it. The copyright infringement is the basis of the claim, at least in part (infringement of a copyright).

It is an example of Federal vs. State preemption. Where the cause of action arises under a claim whose nature would be reasonably within the scope of an existing Federal IP statute (35 USC, 17 USC, etc) the state law is preempted. Source code licenses are often a grant of a copyright license, for example (the cause of action you have against someone who uses the code is copyright infringement). The copyright license is a Federal right, not a state right. Attempt to generate or bring claims under a right that resembles that Federal right under state law will (claim is copyright subject matter, and state right is within general scope of copyright law) end up under Federal law, not state law.

The likely copyright extraterritoriality of the first claim in the Artifex case pushes the first claim down to state interpretation due to lack of jurisdiction (infringement is out of country). The state would need to decide if there was merely a license right, or if a contract was formed around the license by actions or reliance of the parties. They found evidence the parties gave notice the license was part of the agreement, and thus this particular claim can be treated as arising under contract breach. The second claim is different in that US infringements may have occurred.