ci: fix license header check by pinning copyright-year to 2025

skywalking-eyes defaults to current year (2026) when validating
copyright headers, causing all 141 .go files to fail. Pin
copyright-year to '2025' to match existing headers.

Author: xzxiong

.licenserc.yml

@@ -2,6 +2,7 @@ header:
   license:
     spdx-id: Apache-2.0
     copyright-owner: Matrix Origin
+    copyright-year: '2025'
   paths-ignore:
     - 'docs/'
     - 'examples/'