Add Go 1.26 to GitHub Actions test matrix

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

Author: appleboy

.github/workflows/go.yml

@@ -28,7 +28,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        go: [1.24, 1.25]
+        go: [1.24, 1.25, 1.26]
         include:
           - os: ubuntu-latest
             go-build: ~/.cache/go-build