patch: Remove file-based token cache

[christian-kreuzberger-dtx]

Removing the file-based token cache, as it creates problems when having multiple dynatrace-mcp-server instances running (e.g., mutliple environments).

Also, the cache was only consumed when restarting the server (e.g., while developing). It's not really needed when running this in a productive setup, as you wouldn't restart the server all the time.

[github-actions]

📦 Package.json Changes Detected

This PR modifies package.json. Please review the following changes carefully, and tick the following checklist boxes:

Checklist for Reviewers

• Verify that new and/or updated dependencies are necessary and from trusted sources
• Review any script changes for (security) implications
• Verify whether a new version should be released after merging the PR

Package.json Diff

diff --git a/package.json b/package.json
index 0c2e274..3f802a5 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@dynatrace-oss/dynatrace-mcp-server",
-  "version": "0.9.0",
+  "version": "0.9.1",
   "mcpName": "io.github.dynatrace-oss/Dynatrace-mcp",
   "description": "Model Context Protocol (MCP) server for Dynatrace",
   "keywords": [

---

This comment was automatically generated by the PR Package.json Comment workflow.