build: Rebase act-runner container image

.gitea/workflows/actions.yaml

@@ -39,6 +39,7 @@ jobs:
 
   build_image:
     name: Build image
+    container: code.spamasaurus.com/djpbessems/act-runner-extended:1.0.0-cth20250815
     runs-on: ubuntu-latest
     needs: semrel_dryrun
     steps:
@@ -48,15 +49,9 @@ jobs:
         run: |
           apt-get update && \
           apt-get install -y \
-            gettext \
-            genisoimage \
-            libguestfs-tools \
             linux-image-generic \
             linux-modules-extra-$(uname -r) \
-            linux-headers-generic \
-            qemu-system-x86 \
-            qemu-utils \
-            supermin
+            linux-headers-generic
 
           mkdir -p \
             $PWD/ubuntu-vm \