ci: skip CI for documentation-only changes

Add paths-ignore to skip workflow runs when only README, LICENSE,
or example files are modified.

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

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

Author: himekifee

.github/workflows/server-test.yml

@@ -5,8 +5,16 @@ on:
     branches: [main]
     tags:
       - "v*"
+    paths-ignore:
+      - "**.md"
+      - "LICENSE"
+      - "example/**"
   pull_request:
     branches: [main]
+    paths-ignore:
+      - "**.md"
+      - "LICENSE"
+      - "example/**"
   workflow_dispatch:
     inputs:
       mc_version: