onnxruntime

48163990 - Enable WebGPU CI for WebGPU plugin EP release branches (#32090)

Enable WebGPU CI for WebGPU plugin EP release branches (#32090) ### Description <!-- Describe your changes. --> Enable WebGPU CI for WebGPU plugin EP release branches (`plugin-ep-webgpu/rel-*`). ### Motivation and Context <!-- - Why is this change required? What problem does it solve? - If it fixes an open issue, please link to the issue here. --> Additional test coverage for release branch changes. Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>