feat: Add pipeline run parallelism config

[sduvvuri1603]

Description of your changes:

• Added the pipeline_run_parallelism field in PipelineConfig (proto, Go/Python bindings, DSL, compiler) and plumbed it into the generated workflow bundle and Kubernetes platform spec.
• Updated backend logic to persist the value in kfp-pipeline-config, apply it to Argo spec.parallelism, and covered it with TestCreateRun_PipelineRunParallelismConfigMap; regenerated proto goldens.
• Refreshed docs and sample pipeline (pipeline_with_workspace.py/.yaml), verified the compiled output includes pipelineRunParallelism: 3, captured before/after runs showing the ConfigMap entry, and confirmed the field in the compiled workflow YAML via the DSL compiler.

[google-oss-prow]

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[google-oss-prow]

Hi @sduvvuri1603. Thanks for your PR.

I'm waiting for a kubeflow member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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[alyssacgoins]

/retest

[google-oss-prow]

@sduvvuri1603: Cannot trigger testing until a trusted user reviews the PR and leaves an /ok-to-test message.

In response to this:

/retest

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[hbelmiro]

/ok-to-test

[hbelmiro]

/retest