Bump Go version to 1.24.6 across workflows and go.mod files for consistency and latest features. Update dependencies in scripts/local-gitea/seeder/go.mod and go.sum, including code.gitea.io/sdk/gitea and indirect packages, to their latest versions.
Introduce scripts, configs, and Go tools for local Gitea integration testing. Includes workflow for GitHub Actions, seeding and test scenario configuration, runner and seeder binaries, and supporting shell scripts. Updates .gitignore to exclude Gitea test binaries.