Revert "chore(uv[cooldown]): Exempt ruff from release cooldown"

why: ruff 0.16.0 published 2026-07-23T19:10Z and has now cleared uv's
3-day supply-chain cooldown, so the resolver reaches it unaided. The
`ruff>=0.16.0` floor is what holds the version; leaving the exemption
would permanently opt ruff out of the cooldown guard.

what:
- Drop `ruff = false` from `[tool.uv.exclude-newer-package]`
- Relock: the setting is recorded in `uv.lock`, so removing it forces a
  re-resolve. ruff stays at 0.16.0 and no other package moves.

This reverts commit 4660181.

Author: tony

pyproject.toml

@@ -160,10 +160,6 @@ sphinx-gp-sitemap = false
 sphinx-gp-theme = false
 sphinx-ux-autodoc-layout = false
 sphinx-ux-badges = false
-# TEMPORARY - REVERT BEFORE MERGE. ruff 0.16.0 released 2026-07-23 and is
-# still inside the 3-day cooldown, so the resolver cannot see it. Drop this
-# line once the cooldown clears; the version floor is what holds ruff 0.16.
-ruff = false
 
 [tool.mypy]
 python_version = "3.10"