SWPROT-8953: ci: github: Release with token

By default github limit to context allows to create package

The expected error is:

HTTP 403: Resource protected by organization SAML enforcement.
You must grant your Personal Access token access to this organization.

Relate-to: https://github.com/settings/tokens
Origin: #5
Signed-off-by: Philippe Coval <philippe.coval@silabs.com>

Author: rzr

.github/workflows/build-rootfs.yml

@@ -39,4 +39,4 @@ jobs:
           files: build/dist/*
           # yamllint disable-line rule:line-length
           # TODO: Sign asset: https://github.com/softprops/action-gh-release/issues/580#2025
-
+          token: ${{ secrets.GH_UNIFY_ACCESS_TOKEN }}