Analog audio on iMac 2019.1 with Ubuntu 24.04.4 requires corrections in sound card rules and missing ALSA UCM for iMac

When I installed Ubuntu 24.04.4 on my 27" iMac version 19.1, analog did not function: Hardware: iMac 19,1 (2019) Audio chip: Cirrus Logic CS8409 (Vendor Id: 0x10138409, Subsystem Id: 0x106b1000)