ci(workflows): refactor update-versions to use full image tags and auto-detect current values

Replace CUDA version suffix inputs with full image tag inputs (e.g.,
2.54.1-py312-cu128) for CUDA and ROCm across py311/py312. Auto-detect
current tags from constants.py and docs before replacement, add
per-input validation with aggregated error reporting, and remove the
unused setup-python step.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: kryanbeane