github: update .github/docker-releases.json

Signed-off-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: crazy-max

.github/docker-releases.json

@@ -5,6 +5,12 @@
     "html_url": "https://github.com/moby/moby/releases/tag/v25.0.3",
     "assets": []
   },
+  "v26.0.0-rc1": {
+    "id": 142822675,
+    "tag_name": "v26.0.0-rc1",
+    "html_url": "https://github.com/moby/moby/releases/tag/v26.0.0-rc1",
+    "assets": []
+  },
   "v25.0.3": {
     "id": 140187402,
     "tag_name": "v25.0.3",