ci: Don't upload ISO artifacts to github

While the ISO artifacts may theoretically be useful for manually testing PRs,
they are quite large...  Given it's easy enough to build ISOs manually locally
for testing, let's just stick with that and not use so many resources :-)

Signed-off-by: Tim Serong <tserong@suse.com>

.github/workflows/build.yml

@@ -31,14 +31,3 @@ jobs:
     # Build ISO
     - name: Run make ci
       run: make ci
-
-    # This gives us ZIP files of ISO images saved against the
-    # workflow run, in case they're useful for manual testing
-    # We're not publishing to releases.rancher.com here, so as
-    # not to potentially collide with ISO images published from
-    # the main harvester repository.
-    - name: Upload artifacts
-      uses: actions/upload-artifact@v4
-      with:
-        name: artifacts_${{ matrix.arch }}
-        path: ./dist/artifacts/*