Add storage.julialang.net to Julia ecosystem domains

Julia's package system redirects artifact downloads from
pkg.julialang.org to storage.julialang.net CDN. Without this domain,
Pkg.add() fails with 403 when fetching package tarballs.

Discovered during v6 build-test experiment validation run.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Mossaka

pkg/workflow/data/ecosystem_domains.json

@@ -74,7 +74,7 @@
   "terraform": ["releases.hashicorp.com", "apt.releases.hashicorp.com", "yum.releases.hashicorp.com", "registry.terraform.io"],
   "haskell": ["haskell.org", "*.hackage.haskell.org", "get-ghcup.haskell.org", "downloads.haskell.org"],
   "kotlin": ["ge.jetbrains.com", "packages.jetbrains.team", "kotlin.bintray.com"],
-  "julia": ["pkg.julialang.org", "julialang.org", "julialang-s3.julialang.org"],
+  "julia": ["pkg.julialang.org", "julialang.org", "julialang-s3.julialang.org", "storage.julialang.net"],
   "java": [
     "www.java.com",
     "jdk.java.net",