Panpsychism is sometimes stated as: All matter is conscious
What is meant by matter here? For example Philip Goff said:
The basic commitment is that the fundamental constituents of reality — perhaps electrons and quarks — have incredibly simple forms of experience
He included only fermions and not bosons, is this common in panpsychist philosophy?
I wouldn't read too much into that. He refers to "the fundamental constituents of reality," which would include all types of particles. Electrons and quarks are only given as examples. If he meant to exclude bosons, he would have said so.
In the interview where he said this, he goes on to say:
And the very complex experience of the human or animal brain is somehow derived from the experience of the brain’s most basic parts.
Bosons, such as photons, are necessary for the physical function of the brain. Thus, if his premise is that consciousness of the brain is derived from the consciousness of its functional parts, he would have to include photons as functional parts and therefore having some simple consciousness.
I suspect he may be excluding photons, which don't experience time. Other force carrying bosons like gluons also seem very simple.
There are many flavours of panpsychist, and more serious modern proposals like OrchOR focus on specific properties of fundamental phenomena, typically systems capable of generating complex behaviour.
Buddhism or at least the Yogacara school can be argued to be panpsychist, but places things like particles within mind. For Buddhist thought 'unencumbered' awareness has a deep universality.
If electrons are conscious I would think photons are conscious entities as well in order to preserve a principle of mental conservation which may be the flip side of matter-energy conservation. Photons can become particle / anti-particles pairs which can then annihilate back to photons. The mind of the photon becomes the minds of the electron positron pair. The physical conservation is backed by mental conservation. What is the inherent nature of particles? Possibly they are minds - subjective points of view on their local environment.
see panpsychism and real mental causation
and scientific animism
Almost all positions of panpsychism claim that an aggregate of objects does not constitute a distinct experience by itself. This position is not a contradiction, as long as the objects themselves can have experience. For example, one does not think of a group of people as a distinct conscious entity apart from the actual people themselves.
Excluding bosons from having this attribute, does not invalidate the claim of panpsychism, nor invalidate any consciousness conservation law, if there is such (whatever the case).
For example a Cooper pair of electrons behaves as a boson, while at the same time it is an aggregate. On the other hand, a photon can also be expressed as a kind of interaction between an electron and a positron.
So aggregates behave as bosons and bosons may be aggregates, thus it is dubious whether it consists of a separate experience apart from what the electrons themselves may have.
Note that there are conditions, under which an aggregate, can be a distinct conscious entity, eg all biological organisms, humans among them, are types of aggregates. So this claim is not absolute.
