ci: leverage renderkit on cni/cns pipeline dockerfiles

[jpayne3506]

Reason for Change:

Issue Fixed:

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests
• relevant PR labels added

Notes:

[Copilot]

Pull Request Overview

This PR enhances the CI process by leveraging renderkit on the CNI/CNS pipeline Dockerfiles. The changes add new environment variables and render commands in the Makefile for pipeline-specific Dockerfile generation, update CNS Dockerfile templates to incorporate new render variables and base image changes, and introduce corresponding CNI Dockerfile templates and generated files.

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
build/images.mk	Adds new PIPE-PATH, SRC_PIPE, and DEST-PIPE variables and a new render command
.pipelines/build/dockerfiles/cns.Dockerfile.tmpl	Updates template comments and render variable references
.pipelines/build/dockerfiles/cns.Dockerfile	Updates autogenerated Dockerfile with revised base images and Windows alias casing
.pipelines/build/dockerfiles/cni.Dockerfile.tmpl	Introduces a new template for CNI with basic Windows and Linux configurations
.pipelines/build/dockerfiles/cni.Dockerfile	Adds the generated Dockerfile for CNI with updated reference to the new template

Comments suppressed due to low confidence (2)

build/images.mk:18

• Consider renaming the variable 'PIPE-PATH' to use underscores (e.g., PIPE_PATH) for clarity and to avoid potential issues with hyphenated variable names in Makefiles.

export PIPE-PATH	?= .pipelines/build/dockerfiles

build/images.mk:20

• Consider renaming 'DEST-PIPE' to use underscores (e.g., DEST_PIPE) to improve readability and consistency with typical Makefile naming conventions.

export DEST-PIPE	?= ${PIPE-PATH}/${PATH}.Dockerfile

[jpayne3506]

Closing in favor of #3606