Fix GitHub Issue kptdev#4432: Resolve Kubernetes version mismatch, YAML serialization, result classification, and test YAML parsing

Fixes applied:
1. Kubernetes Dependency Alignment - Updated all k8s.io modules to v0.35.0
2. YAML Serialization Fix - Added yaml tags alongside json tags in RenderStatus, PipelineStepResult, ResultItem
3. Correct Result Classification Logic - Updated extractResultsFromFnResults to use severity instead of ExitCode
4. Test YAML Parsing Fix - Fixed yaml.MustParse test input with proper multiline YAML

Result: Eliminates dependency/API mismatch, ensures correct YAML output, fixes logic bug in result classification, makes tests valid and reliable

Closes: kptdev#4432

Signed-off-by: NETIZEN-11 <niteshkumar121411@gmail.com>

Author: NETIZEN-11