Update DietPi image url

Signed-off-by: Frank Roth <developer@freakydu.de>

.github/workflows/prerelease-latest.yml

@@ -3,11 +3,11 @@ on:
   push:
     branches:
       - 'main'
-
 env:
   tagName: prerelease-latest
   releaseName: prerelease-latest
   preRelease: true
+  CARGO_TERM_COLOR: always
 jobs:
   release-amd64:
     permissions:
@@ -56,7 +56,7 @@ jobs:
       - name: build release
         uses: pguyot/arm-runner-action@v2
         with:
-          base_image: https://dietpi.com/downloads/images/DietPi_RPi-ARMv8-Bullseye.7z #dietpi:rpi_armv8_bullseye
+          base_image: https://dietpi.com/downloads/images/DietPi_RPi-ARMv8-Bullseye.img.xz #dietpi:rpi_armv8_bullseye
           cpu: cortex-a53
           cpu_info: cpuinfo/raspberrypi_zero2_w_arm64
           bind_mount_repository: true