(Caveat: I wrote this before your previous replies, and so was not clear on what sort of resources you have or what sort of opposition you're expecting.)
It's very difficult to make a dungeon that will stop high-level adventurers - they're pretty much built to
not be stopped by dungeons. My general line of thinking is that if you're in a position to attempt this, you're one of the highest level people around, so it might be better to focus on designing a dungeon that will put them in situations where you can fight them yourself, on advantageous terms. Ambush points, environmental damage you're immune to, and so on.
- people wishing themselves to the ritual site (or trying to wish me out)
- using teleportation / gaseous form to bypass all the traps
Forbiddance and/or dimension lock is the obvious option for teleportation. I'd think they'd cover wishes as well, but unsure. Gaseous form is foiled by making things airtight, and/or environmental harm that bypasses the damage reduction from it. (Gaseous form moves pretty slow.)
- digging/earthgliding in
Environmental hazards, contact poison inside the walls, burrowing monsters that can attack them while they're trying it? Antimagic fields that surround but don't reach into the dungeon? (I think there's a way to craft them as a trap, don't remember for sure.) Also, Walls of Force, if you can.
- earthquaking the whole thing from the outside without even going in.
Have the ritual room more than 80 feet down so they can't reach it with an earthquake from the surface. Also, Walls of Force, if you can.
Haven't looked into costs, so I'm not sure if this makes sense, but at the moment, one idea I'm imagining is that I might set up a ritual room - or an entire dungeon, resources permitting - with layered Force and metal walls, with a region of overlapping antimagic fields surrounding but not reaching into it, submerged in magma. (Volcano lairs are a classic.) Of course, I'd prepare in advance by buying up or destroying any items of fire immunity I could find... need to come up with a way to sense through molten rock, too. Hm.