Release: Publish Gitea 1.26.3

[lunny]

• Check cowdin sync
• Check possible Golang versions upgraded
  • Check whether XGo is ready for new Golang version
  • Check whether golang-alpine image is ready for the new Golang version
• Prepare a new changelog and update CHANGELOG.md docs: add changelog for 1.26.3 #38166
• Close milestone of 1.26.3
• Release 1.26.3 from release/v1.26 branch
  • Generate changelog_1.26.3.md from merged CHANGELOG.md
  • Frontend changelog to main branch
  • Tag 1.26.3 with git tag -s -f changelog_1.26.3.md v1.26.3 and Push to Github
  • Wait for the release created and check whether the release artifacts generated
    • Check whether Github release attachments are generated and normal
    • Check whether the binaries generated under https://dl.gitea.com/gitea/1.26.3/ and normal
    • Check whether docker images are generated https://hub.docker.com/r/gitea/gitea/tags?page=&page_size=&ordering=&name=1.26.3
  • If the release does work then make it out of draft so that it's public for everyone.
• Update "version.json" to 1.26.3
• Official packages updated
  • Homebrew https://github.com/Homebrew/homebrew-core/blob/master/Formula/g/gitea.rb
  • Snap https://snapcraft.io/gitea
  • Helm Chart For Gitea
  • Terraform
• Update documentation's latest stable version to 1.26.3
• Confirm blog is ready and merge
• Official website download button version
• Announce the 1.26.3 release.