chore: cerate prepare-release and release workflow for codegen 3.0

[ewaostrowska]

This PR improves the Swagger Codegen 3.0 release automation by:

1. Enabling PR creation during dry_run for prepare/release flows.
2. Removing duplicated embedded Python file-update logic by extracting a shared helper.

Changes

Workflow updates

• Updated GitHub App token action in new workflows:
  • .github/workflows/prepare-release-3.yml
  • .github/workflows/release-codegen-3.yml

Dry-run PR behavior

• prepare-release-3.yml
  • PR creation now runs even when dry_run=true.
  • Token generation for PR creation is no longer gated by dry_run.
  • Updated dry_run input description to clarify PR is still created.
• release-codegen-3.yml
  • post_release_pr now runs even when dry_run=true.
  • Updated dry_run input description to clarify PR is still created.
• Deploy/publish protections remain unchanged:
  • Maven deploy still gated by skip_maven_deploy and dry_run.
  • Docker push and Rancher deploy still gated and skipped in dry_run.

CI script deduplication

• Added shared helper:
  • CI/release/update-codegen-release-files.py
• Refactored:
  • CI/release/prepare-codegen-release.sh
  • CI/release/post-codegen-snapshot.sh
• Both scripts now call the shared Python helper (prepare / post modes) instead of maintaining duplicated inline Python.

Why

• Supports safe workflow testing while still producing reviewable PR output.
• Reduces maintenance risk and drift by centralizing release-file transformation logic.

[Copilot]

Pull request overview

This PR replaces the old monolithic Swagger Codegen 3.0 release workflow with separate prepare/release automation plus shared Bash helpers for version resolution and release state handling.

Changes:

• Adds reusable release helper scripts under CI/release for version checks, prepare-release edits, and post-release snapshot updates.
• Introduces new prepare-release-3.yml and release-codegen-3.yml workflows to split preparation, validation, publishing, Docker, deployment, and follow-up PR creation.
• Removes the legacy release-full-3.yml workflow in favor of the new staged flow.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 17 comments.

Show a summary per file

File	Description
CI/release/common.sh	Adds shared shell helpers for version validation, Maven metadata lookup, artifact existence checks, and workflow outputs.
CI/release/resolve-release-versions.sh	Resolves codegen/generators versions and deployment decisions for the new release workflow.
CI/release/prepare-codegen-release.sh	Prepares release-version changes, release notes, and release-file updates before opening a PR.
CI/release/post-codegen-snapshot.sh	Prepares the next snapshot bump after a release.
.github/workflows/prepare-release-3.yml	Adds a manual prepare-release workflow that validates/builds and opens a release PR.
.github/workflows/release-codegen-3.yml	Adds the main 3.0 release workflow covering validation, optional generators release, codegen release, Docker, deploy, and post-release PRs.
.github/workflows/release-full-3.yml	Removes the previous all-in-one 3.0 release workflow.

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[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 7 comments.

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[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 7 comments.

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