ci: adjust workflows to rootfs-image-coco-addon

Add rootfs-image-coco-addon to the build-asset-rootfs matrix in the
amd64, arm64 and s390x static tarball workflows so the CoCo addon image
is built as part of CI alongside the other rootfs images.

Signed-off-by: Fabiano Fidêncio <ffidencio@nvidia.com>
Assisted-by: Cursor <cursoragent@cursor.com>

.github/workflows/build-kata-static-tarball-amd64.yaml

@@ -170,7 +170,7 @@ jobs:
       matrix:
         asset:
           - rootfs-image
-          - rootfs-image-confidential
+          - rootfs-image-coco-addon
           - rootfs-image-mariner
           - rootfs-image-nvidia-gpu
           - rootfs-image-nvidia-gpu-confidential

.github/workflows/build-kata-static-tarball-arm64.yaml

@@ -160,7 +160,7 @@ jobs:
       matrix:
         asset:
           - rootfs-image
-          - rootfs-image-confidential
+          - rootfs-image-coco-addon
           - rootfs-image-nvidia-gpu
           - rootfs-initrd
     concurrency:

.github/workflows/build-kata-static-tarball-s390x.yaml

@@ -138,7 +138,7 @@ jobs:
       matrix:
         asset:
           - rootfs-image
-          - rootfs-image-confidential
+          - rootfs-image-coco-addon
           - rootfs-initrd
           - rootfs-initrd-confidential
     concurrency: