Ubuntu 22.04.1 LTS Desktop includes the 5.15 kernel on it, which is what is used with the live session, and installed too.
That ISO can be found at
with the manifest or contents found at
If you examine the manifest you'll see it contains
linux-generic-hwe-22.04 5.15.0.43.44
linux-image-5.15.0-43-generic 5.15.0-43.46
which is what you're asking for, HOWEVER as its the HWE or Hardware Enablement kernel that is installed by default for Ubuntu Desktop, thus it'll upgrade to 6.8 which is the current HWE kernel (https://wiki.ubuntu.com/Kernel/LTSEnablementStack)
Media that uses/installs the GA kernel stack will remain 5.15 after upgrade, but Ubuntu Desktop ISOs since 20.04 have come with the HWE kernel stack.
The GA kernel (package I also listed) is also found on the installation media as an OEM option, but it is not installed during a normal install UNLESS it's detected as a better option as part of OEM kernel processing
Ubuntu Server ISOs install with the GA kernel stack, as do older flavor media at 22.04 & 22.04.1 (later or .2 & higher flavor media uses HWE same as Ubuntu Desktop)