I downloaded the most recent version of Raspberry Pi OS, saved a wpa_supplicant.conf and a ssh file in the boot partition, but I was not able to ssh to the pi with ssh pi@raspberry.local as the standard password raspberry did not work.
How can I set up my pi headless without using rpi-imager or stuff like that?
There is no standard user and password anymore in the new Raspberry Pi OS image. https://www.raspberrypi.com/news/raspberry-pi-bullseye-update-april-2022/
To create one a file named userconf has to be saved to the boot partition containing just one line:
username:<encrypted-password>
You get the encrypted password by running echo 'yourpassword' | openssl passwd -6 -stdin on a linux machine with openssl installed.
If you want to use the old standard password raspberry and the pi username, paste this line to your userconf:
pi:$6$6jHfJHU59JxxUfOS$k9natRNnu0AaeS/S9/IeVgSkwkYAjwJfGuYfnwsUoBxlNocOn.5yIdLRdSeHRiw8EWbbfwNSgx9/vUhu0NqF50