mesh-build-go: push each done archive to the artifact store from its own process and answer its reference (issue 1587, S1-S4, ADR 0498 §1 §2, lead decision L9)

After the build ended the module pushes the packed bundle or archive with mesh-sdk's
PushBlob under <module>/<artifact> by its digest, a candidate's as a trunk build's, and the
step answers artifact-store://<module>/<artifact>/blobs/<digest> instead of a path. A push
that fails fails the step not stored: <artifact>: <the store's words>. The packed bytes are
never written to the node. The manifest requires artifact-store and places its address.

modules/mesh-build-go/module.json

@@ -31,7 +31,8 @@
   ],
   "requires": [
     "forge-account",
-    "go-toolchain"
+    "go-toolchain",
+    "artifact-store"
   ],
   "own-secrets": {
     "broker": "${dir:state}/broker"
@@ -109,6 +110,14 @@
       "mode": "0644",
       "template": "files/gitconfig"
     },
+    {
+      "id": "registry",
+      "type": "file",
+      "path": "${dir:state}/registry",
+      "owner": "mesh-build-go",
+      "mode": "0644",
+      "template": "files/registry"
+    },
     {
       "id": "git",
       "type": "package",