InRelease’ changed its ‘Suite’ value from ‘testing’ to ‘stable’: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.

If someone gets it as well then the solution is relatively simple. Run apt-get --allow-releaseinfo-change update

Before

x@pi-server-02  /etc/apt  sudo apt-get update
Hit:1 https://download.docker.com/linux/raspbian bullseye InRelease
Hit:2 https://deb.nodesource.com/node_10.x bullseye InRelease
Get:3 http://raspbian.raspberrypi.org/raspbian bullseye InRelease [15.0 kB]
Reading package lists… Done
E: Repository 'http://raspbian.raspberrypi.org/raspbian bullseye InRelease' changed its 'Suite' value from 'testing' to 'stable'
N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.

After

x@pi-server-02  /etc/apt  sudo apt-get --allow-releaseinfo-change update
Hit:1 https://download.docker.com/linux/raspbian bullseye InRelease
Hit:2 https://deb.nodesource.com/node_10.x bullseye InRelease                    
Get:3 http://raspbian.raspberrypi.org/raspbian bullseye InRelease [15.0 kB]      
Get:4 http://raspbian.raspberrypi.org/raspbian bullseye/main armhf Packages [13.2 MB]
Get:5 http://raspbian.raspberrypi.org/raspbian bullseye/contrib armhf Packages [60.2 kB]                                                                                                                            
Get:6 http://raspbian.raspberrypi.org/raspbian bullseye/non-free armhf Packages [106 kB]                                                                                                                            
Get:7 http://raspbian.raspberrypi.org/raspbian bullseye/rpi armhf Packages [1360 B]                                                                                                                                 
Fetched 13.4 MB in 22s (621 kB/s)                                                                                                                                                                                   
Reading package lists... Done
N: Repository 'http://raspbian.raspberrypi.org/raspbian bullseye InRelease' changed its 'Suite' value from 'testing' to 'stable'

x@pi-server-02  /etc/apt  sudo apt-get update                           
Hit:1 https://deb.nodesource.com/node_10.x bullseye InRelease
Hit:2 https://download.docker.com/linux/raspbian bullseye InRelease                                           
Hit:3 http://raspbian.raspberrypi.org/raspbian bullseye InRelease                                             
Reading package lists... Done