Pin linter version to v1.61.0 in the build workflow

By default, the linter uses the latest version, which is currently v1.62.0.
In v1.62.0, a new `max-public-structs` linter was added.
Significant changes are required in our codebase to enable this linter.

This PR also aligns the linter version with the one specified in the Makefile target.

.github/workflows/build_test.yml

@@ -54,6 +54,8 @@ jobs:
           cache: false
       - name: Lint
         uses: golangci/golangci-lint-action@v6
+        env:
+          GOLANGCI_LINT_VERSION: v1.61.0
         with:
           args: --timeout 10m0s
       - name: Verify all generated pieces are up-to-date