The reroute node used to be a bit special in the sense that its data type was
only stored in the sockets. However, typically, the ground truth data should be
stored in the node storage and then the socket types are derived from that.
For users, there should not be a noticable difference. However, from Python
it's not possible to modify the socket type directly on the socket anymore.
This is forbidden for other built-in nodes already too.
Instead, one can use the new `reroute_node.socket_idname` property to change
the type of a node. This internally also recreates the sockets with the correct
type.
Pull Request: https://projects.blender.org/blender/blender/pulls/121146
c40dc9aa03