framework: add resolute (Ubuntu 26.04) image to the daily matrix

Adds ubuntu-resolute amd64 and arm64 to docker-per-arch and a
matching multi-arch manifest entry in join-arches. Mirrors the
existing noble rows in shape and runner choice (ubuntu-24.04 hosts
with buildx + QEMU; the host kernel doesn't drive the produced
image).

armbian/build's distributions/resolute/support is already 'csc' as of
the latest sync, so consumers of these images can target resolute end
to end.

Author: igorpecovnik

.github/workflows/update_docker.yml

@@ -31,6 +31,8 @@ jobs:
           - { os: "debian", release: "trixie", arch: "arm64", runner: "ubuntu-24.04-arm" }
           - { os: "ubuntu", release: "noble", arch: "amd64", runner: "ubuntu-24.04" }
           - { os: "ubuntu", release: "noble", arch: "arm64", runner: "ubuntu-24.04-arm" }
+          - { os: "ubuntu", release: "resolute", arch: "amd64", runner: "ubuntu-24.04" }
+          - { os: "ubuntu", release: "resolute", arch: "arm64", runner: "ubuntu-24.04-arm" }
     runs-on: "${{ matrix.runner }}"
     name: "${{ matrix.release }} ${{ matrix.arch }} (${{ matrix.os }})"
     env:
@@ -183,6 +185,14 @@ jobs:
             ghcr.io/${{ github.repository }}:armbian-ubuntu-noble-arm64-latest
           docker buildx imagetools inspect ghcr.io/${{ github.repository }}:armbian-ubuntu-noble-latest
 
+      - name: ubuntu-resolute - Create and push multi-arch manifest using buildx
+        run: |
+          docker buildx imagetools create -t \
+            ghcr.io/${{ github.repository }}:armbian-ubuntu-resolute-latest \
+            ghcr.io/${{ github.repository }}:armbian-ubuntu-resolute-amd64-latest \
+            ghcr.io/${{ github.repository }}:armbian-ubuntu-resolute-arm64-latest
+          docker buildx imagetools inspect ghcr.io/${{ github.repository }}:armbian-ubuntu-resolute-latest
+
   keepalive:
     if: ${{ github.repository_owner == 'armbian' }}
     name: Keep Alive