Bump actions/download-artifact from 2 to 4.1.7

[bakpaul]

Hello.

Download artifact is also used later in the file, you might want to modify the version too : https://github.com/SofaDefrost/SoftRobots.Inverse/pull/41/files#diff-b803fcb7f17ed9235f1e5cb1fcd2f5d3b2838429d4368ae4c57ce4436577f03fR161