Update golangci-lint action to v9 and v2.6.1

Bump golangci-lint GitHub Action from v6 to v9 and update linter version from v1.64.8 to v2.6.1 for improved linting and compatibility.

Author: jferrl

.github/workflows/ci.yaml

@@ -14,9 +14,9 @@ jobs:
         with:
           go-version: "1.25.x"
       - name: golangci-lint
-        uses: golangci/golangci-lint-action@v6
+        uses: golangci/golangci-lint-action@v9
         with:
-          version: v1.64.8
+          version: v2.6.1
 
   test:
     runs-on: ubuntu-latest