Occult Adventures details psychic magic, not “psionics,” which is notably not “magic” at all. Paizo has never printed any psionic material—the psionic material for Pathfinder is all third-party, most notably from Dreamscarred Press. As both a disclaimer and for backing up my answer, I have worked for Dreamscarred Press, specifically on their efforts to clarify the psychic–psionic confusion.
Because there was a lot of confusion—the choice to label the material from Occult Adventures “psychic,” combined with the fact that Paizo re-used some of the Open Game Content names of psionic powers for psychic spells, caused a lot of people to think they were the same. DSP saw an immediate drop in sales as people moved to the “official” form of “psionics,” and Paizo got some bad PR over it, since they had previously claimed they would not pursue psionics and this was part of what induced DSP to move from 3.5e to Pathfinder in the first place. DSP would go on to produce an entire line of products devoted to cleaning up this mess and trying to justify psionics’ existence in a game that also has psychic magic (this is what I worked on).
Tellingly, Paizo has avoided repeating this mistake: in Pathfinder 2e, this form of magic is known as “occult magic.”
Now then, history lesson out of the way, your question: does dispel magic work on psionics, or psychic/occult magic?
Psychic magic is just that, magic, and dispel magic undoes magic. No part of Occult Adventures suggests otherwise. Psychic magic uses different spellcasting components (there are no verbal or somatic components, and instead there are thought and/or emotion components), and psychic magic can do “undercasting” which other kinds of magic cannot do, but ultimately, it is still magic, psychic spells are still spells, and so on. This becomes very difficult to “prove,” however, as nothing ever says anything about it being dispellable—that’s just the default for magic.
Psionics is not magic, and so that requires a bit more care. However, under Dreamscarred Press’s rules, psionics is “transparent” to magic—that is, magic affects psionics just the same as it does magic, and psionics affects magic just as it does psionics. Dispel magic and dispel psionics can both dispel both magic and psionics, despite the names. This is all described in the basic rules for psionics under “Combining Psionic and Magical Effects”.
DSP does acknowledge a highly-discouraged potential variant in which magic and psionics are not transparent. This is discussed very briefly in Ultimate Psionics, and it explicitly warns the GM that if they wish to pursue a non-transparent situation, they have a lot of work to do to get that functioning correctly. Which is why it is so heavily discouraged. However, if things are not transparent, then you could not dispel a psionic power with dispel magic, and would have to use dispel psionics instead.
Again, Occult Adventures doesn’t even suggest that psychic magic could even possibly be separate enough from arcane and divine magic that dispel magic wouldn’t work.