Realistically, any LTS distro from a netinstaller or minimal image that can use a kiosk compositor like cage. So, the usual suspects of Debian, OpenSUSE, AlmaLinux, RockyLinux (or a derivative of one if the native distro doesn’t support Raspberry Pi). Then you just have cage open the browser of choice on startup (e.g. chromium --kiosk <url>) and you have a lightweight and relatively secure web kiosk.