fix(ci): pin lint job to Go 1.24 to match golangci-lint compatibility

golangci-lint latest is built with Go 1.24 and fails on Go 1.26 stdlib.
Pin the lint job's Go version to match.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: elucidsoft

.github/workflows/ci.yml

@@ -36,7 +36,7 @@ jobs:
 
       - uses: actions/setup-go@v5
         with:
-          go-version: stable
+          go-version: '1.24'
 
       - uses: golangci/golangci-lint-action@v6
         with: