Use ubuntu-latest for Debusine image builds

The Debusine builder images only package workflow tooling; package compilation happens remotely in Debusine, so the image publishing workflow should not be pinned to arm64 runners.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: simonbeaudoin0935

.github/workflows/qcom-debusine-container-build-and-upload.yml

@@ -1,7 +1,7 @@
 name: Debusine Container Build And Upload
 description: |
   Builds and uploads to GHCR the Debian builder images used by the Debusine-based
-  reusable workflows. Images are built natively on an arm64 runner and published
+  reusable workflows. Images are built on standard GitHub-hosted runners and published
   on push, scheduled runs, and manual dispatches.
 
 on:
@@ -35,9 +35,9 @@ env:
   IMAGE_NAME: debusine-pkg-builder
 
 jobs:
-  build-debian-arm64:
+  build-debian:
     name: Build ${{ matrix.suite }} image
-    runs-on: ubuntu-24.04-arm
+    runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix: