chore: add GitHub welcome workflow for new contributors

[aniketpati1121]

What this PR does

This PR adds a GitHub Actions–based welcome workflow to the Kubeflow Pipelines repository.

The workflow automatically welcomes first-time contributors when they open an issue or a pull request and provides helpful guidance and links to get started.

Why this is needed

• Improves onboarding experience for new contributors
• Encourages participation and smooth contribution workflow
• Provides links to the Contributing Guide and community Slack channels

Workflow details

• Trigger: First-time pull_request and issue events
• Messages are tailored for PRs and issues separately
• Uses the actions/first-interaction GitHub Action

Additional notes

• This workflow is inspired by the existing workflow in kubeflow/sdk
• Once merged, new contributors will see a friendly welcome message automatically.

fixes #12526

[google-oss-prow[bot]]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: Once this PR has been reviewed and has the lgtm label, please assign hbelmiro for approval. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• .github/OWNERS

Approvers can indicate their approval by writing /approve in a comment Approvers can cancel approval by writing /approve cancel in a comment

[google-oss-prow[bot]]

Hi @aniketpati1121. 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.

I understand the commands that are listed here.

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.

[aniketpati1121]

Thank you @aniketpati1121! I think we should standardize this across all Kubeflow projects /assign @kubeflow/wg-pipeline-leads

Thanks for the suggestion! I agree that standardizing this across all Kubeflow projects will really help contributors.

[kramaranya]

Thanks a lot, @aniketpati1121! /lgtm

[google-oss-prow[bot]]

New changes are detected. LGTM label has been removed.

[aniketpati1121]

Hi @hbelmiro, could you please take a quick look at this PR for review? Thanks!