In games like Deus Ex and Dishonored, the player can leave combat ability on the table and go through the entirety of the game without fighting anyone. Stacking boxes to get to where they need, sneaking through complexes, and talking down the big-bad are all options that get you to credits. If you could coordinate with your team, i’m certain you could get a similar playstyle going in quite a satisfying way in PF2e. Realistically though, people come to this game to roll dice with their bardiches out, so you’re more likely than not going to have a standard grab bag of murderhobos as your teammates.
With friends like these, how viable are your Adam Jensens, your Faith Mirrorsedges, or your Frisk Undertales? Can you really set up a character that doesn’t use any combat ability and find success in a standard adventure path, relying on your team to take on your share of the combat encounter budgets for you? In what ways would you pull your weight to justify the character’s “slot” in the party?
Pathfinder is ultimately a game about killing things and taking their stuff, so no matter what you do, you’re going to need something to do in combat.
Now, can you play a “technical pacifist” who never rolls a single attack? Probably! A bard or another spellcaster (or maybe another build with the Marshal archetype?) could focus on buffs and debuffs, Demoralize actions, Recall Knowledge, etc.
Agreed, things like the Summoner’s Eidolon also come to mind. As OP said, I imagine you could also find a group and adventure, potentially homebrewed, who just wanted to do an investigation/exploration and avoid fights but that is not bog standard Pathfinder and if that’s your jam a different system focused on that style of play might be better. But back to your original question, I think it’d be tough as you need to do something in combat.
It’s entirely possible to play in a game where there are nonviolent solutions to every encounter. The main thing is that it would require buy in from the GM and the rest of the table. It depends on the genre of game your GM wants to run. Similar to how a hard boiled detective would be out of place in a game centered around a travelling carnival, a pacifist would be out of place in a dungeon crawler. That’s not to say you can’t do it, but you would have to accept that your character would be a fish out of water.
A pacifist could work well in a few genres though. A murder mystery, a spy thriller, or political intrigue story would probably feature little to no combat.
Your character needs to be okay with participating in killing things, since that’s the game. But it’s entirely possible to build a character such that striking/taking offensive action is not their typical rinse and repeat. You should probably still be okay with killing as a last resort though, since otherwise the party is gonna be pissed if you get into a situation where you attacking could save someone else’s life.