CME-541: Enable Renovate updates for App Insights agent

Add renovate datasource comment to Dockerfile and regexManagers
to renovate.json to enable automatic dependency updates.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: chrisworthcgi

.github/renovate.json

@@ -13,5 +13,13 @@
       "matchPackageNames": ["org.junit.platform"],
       "allowedVersions": "1.9.2"
     }
+  ],
+  "regexManagers": [
+    {
+      "fileMatch": ["^Dockerfile$"],
+      "matchStrings": [
+        "datasource=(?<datasource>.*?) depName=(?<depName>.*?)( versioning=(?<versioning>.*?))?\\sARG .*?_VERSION=(?<currentValue>.*)\\s"
+      ]
+    }
   ]
 }

Dockerfile

@@ -1,3 +1,4 @@
+# renovate: datasource=github-releases depName=microsoft/ApplicationInsights-Java
 ARG APP_INSIGHTS_AGENT_VERSION=3.4.9
 ARG PLATFORM=""
 # Application image