Add renovate for updating docker images (onnx#7572)

### Motivation and Context

dependabot has not function to update the docker image

---------

Signed-off-by: Andreas Fehlner <fehlner@arcor.de>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: andife

renovate.json5

@@ -0,0 +1,35 @@
+// Copyright (c) ONNX Project Contributors
+//
+// SPDX-License-Identifier: Apache-2.0
+
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "extends": [
+    "config:recommended"
+  ],
+  // Package-specific rules for grouping and enabling updates
+  "packageRules": [
+    {
+      // Group manylinux Docker images together in a single PR
+      "matchDatasources": ["docker"],
+      "matchPackageNames": ["quay.io/pypa/manylinux_2_28_x86_64", "quay.io/pypa/manylinux_2_28_aarch64"],
+      "enabled": true,
+      "groupName": "manylinux docker images"
+    }
+  ],
+  // Custom managers for dependencies not auto-detected by Renovate
+  "customManagers": [
+    {
+      // Detect manylinux Docker images in GitHub Actions workflows
+      // Example: uses: docker://quay.io/pypa/manylinux_2_28_x86_64:2025.10.10-1
+      "customType": "regex",      
+      "fileMatch": ["^\\.github/workflows/release_linux\\.yml$"],
+      "matchStrings": [
+        "uses:\\s*docker://quay\\.io/pypa/(?<depName>manylinux_[^:]+):(?<currentValue>[0-9]{4}\\.[0-9]{2}\\.[0-9]{2}-[0-9]+)"
+      ],
+      "datasourceTemplate": "docker",
+      "depNameTemplate": "quay.io/pypa/{{{depName}}}",
+      "versioningTemplate": "loose"
+    }
+  ]
+}