fix: Update Go version to 1.25 in CI configuration

Author: kyoungho

.github/workflows/ci.yml

@@ -18,7 +18,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v4
       with:
-        go-version: '1.21'
+        go-version: '1.25'
 
     - name: Cache Go modules
       uses: actions/cache@v3