artifact: honor Retry-After on HTTP 429 and prepare 6.3.0

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@actions/artifact",
-  "version": "6.2.2",
+  "version": "6.3.0",
   "preview": true,
   "description": "Actions artifact lib",
   "keywords": [