chore: simplify toolchain release workflows

[rozsazoltan]

Summary

Simplifies the toolchain GitHub Actions release surface after the unified verzly toolchain structure was merged.

The repository now exposes only the workflows that are still needed for the single-repo release model.

Changes

• Replace the redundant release workflow set with a single Release workflow.
• Keep only the required workflow entrypoints:
  • Release
  • Delete Release
  • Test
• Remove obsolete release workflow entrypoints:
  • Release All
  • Release Toolchain
  • Release Verzly
  • Release Build Assets
  • Update Floating Tags
• Move build asset generation into the main release flow.
• Rely on github-release finalize to update floating release tags.

Notes

Floating tag updates are now part of the normal release finalization step, so a separate workflow is no longer needed.