feat(release): automate post-upgrade tasks by code generating upgrade handler and auto-increasing e2e version

[p0mvn]

Background

The post-release process in #2608 can be fully automated.

Suggested Design

• Once a release a created, we can trigger the post-release GitHub Action
• The GitHub Action runs a script to generate an empty "next version" upgrade handler in app/upgrades
  • Some earlier code gen examples can be found here: https://github.com/osmosis-labs/osmosis/blob/roman/twap-e2e/cmd/querygen/README.md#L0-L1
• The e2e upgrade version is increased by the script
• Pull request with the changes is automatically created
  • Our import paths action can be a helpful reference: https://github.com/osmosis-labs/osmosis/blob/main/.github/workflows/import_paths.yml

Acceptance Criteria

• the script is tested on a personal fork
• Proof PR from personal fork is attached
• E2E test is passing
• E2E test is testing the post-release upgrade handler

[pysel]

hello @p0mvn is this available to work on?

[p0mvn]

Yes, please go ahead. Thank you