ci: build: upload the RAUC bundle at the end of the build

We do not want to be wasteful with the upload traffic we consume,
hence why we did not upload any artifacts previously.
(The sparse image for the eMMC is ~840Mb and the RAUC bundle ~290Mb).

Being able to test the the generated artifacts would however be super
convenient, so upload at least the RAUC bundle for now.

Signed-off-by: Leonard Göhrs <l.goehrs@pengutronix.de>

Author: hnez

.github/workflows/build.yml

@@ -38,6 +38,13 @@ jobs:
             emmc-boot-image \
             tf-a-stm32mp
 
+          # Make the generates images available at a less deeply nested
+          # location for the artifact upload (the directory structure is
+          # preserved in the archive).
+          # Keep in mind that we are in the `build` directory because
+          # `oe-init-build-env` implicitly `cd`s there.
+          mv tmp/deploy/images/lxatac ../images
+
       - name: Print logs of failed jobs
         if: ${{ failure() }}
         shell: python3 {0}
@@ -67,3 +74,11 @@ jobs:
           chmod 600 ~/.ssh/id_ed25519
           rsync -rvx --ignore-existing build/downloads yocto-cache: || true
           rsync -rvx --ignore-existing build/sstate-cache yocto-cache: || true
+
+      - name: Upload RAUC Bundle
+        uses: actions/upload-artifact@v4
+        with:
+          name: rauc-bundle
+          path: images/lxatac-core-bundle-base*
+          compression-level: 0
+          retention-days: 30