ci: migrate all workflows from incus-debian to debian:host runner

- Updated runs-on from incus-debian to debian:host across all workflow files
- Changed audit.yml, ci-cd.yml, ci.yml, fix.yml, security-scanning.yml, and test.yml
- Updated cli-level1-tests.yml from ubuntu-latest to debian:host
- Standardizes runner configuration across all CI/CD pipelines

.gitea/workflows/ci-cd.yml

@@ -6,7 +6,7 @@ on:
 
 jobs:
   build:
-    runs-on: incus-debian
+    runs-on: debian:host
 
     steps:
       - name: Checkout