ci: integrate kube-api-linter into golangci-lint workflow

[moko-poi]

Integrate kube-api-linter into the golangci-lint workflow to enforce Kubernetes API conventions and catch common mistakes in Kubernetes API types.

This PR addresses #675 by:

• Building golangci-lint with the kube-api-linter plugin using golangci-lint custom
• Updating CI workflow to use the custom-built linter
• Adding configuration file for custom plugin management

Changes

1. Custom golangci-lint Configuration

• Added .custom-gcl.yml: Configuration file specifying kube-api-linter plugin (v0.0.0-20251112164541-d94382a24f06) to be built into golangci-lint

2. Makefile Updates

• Modified golangci-lint target (Makefile:214-221): Changed from simple go install to custom build process
  • First installs standard golangci-lint v2.4.0
  • Then builds custom binary with plugins using golangci-lint custom -o $(GOLANGCI_LINT) .custom-gcl.yml
  • Ensures kube-api-linter is available in local development

3. CI/CD Integration

• Modified .github/workflows/golangci-lint.yaml: Replaced golangci/golangci-lint-action with Makefile-based approach
  • Added "Build custom golangci-lint" step to build the linter with plugins
  • Changed "lint" step to use make lint for consistency between local and CI environments

Benefits

• Standards Compliance: Enforces Kubernetes API Conventions
  automatically
• Consistency: Same linter configuration used in both local development and CI
• Maintainability: Centralized plugin configuration in .custom-gcl.yml for easy updates

Testing

• Local testing: Run make golangci-lint && make lint to verify custom linter builds and runs correctly
• CI will automatically build and use the custom linter on all PRs and pushes

References

• kubernetes-sigs/kube-api-linter
• golangci-lint custom plugins documentation