Fix mkarchiso argument parsing in CI

Use -- to separate flags from profile path, preventing mkarchiso
from misinterpreting the -w argument as the profile directory.
Also make rm -rf fail-safe with || true.

.gitea/workflows/build-iso.yaml

@@ -27,8 +27,8 @@ jobs:
 
       - name: Build Arch ISO
         run: |
-          rm -rf "${PWD}/work"
-          mkarchiso -v -c -w "${PWD}/work" -o "${PWD}/out" "${PWD}"
+          rm -rf "${PWD}/work" || true
+          mkarchiso -v -c -w "${PWD}/work" -o "${PWD}/out" -- "${PWD}"
 
       - name: Generate Unique Dynamic Tag
         id: tag