Add ghcr.io/matrixgpt/matrix-chatgpt-bot to Renovate's `ignoreDeps` list

Related to:

- https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3196
- ce893c1b22
- https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3200#issuecomment-2491780481
- https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3856

.github/renovate.json

@@ -20,5 +20,8 @@
 			],
 			"ignoreUnstable": false
 		}
+	],
+	"ignoreDeps": [
+		"ghcr.io/matrixgpt/matrix-chatgpt-bot"
 	]
 }