v8.0.1

Packaging and CI only — no behaviour changes.

Changes

• EOL Rails 7.2 dropped from the matrix (EOL 2026-08-09); CI now runs Ruby 3.3/3.4/4.0 against Rails 8.0/8.1, and the PostgreSQL and MySQL jobs moved to Rails 8.1 (#228)
• the two exclude rules claiming Active Admin 3.2 could not run Rails 8 were deleted: the matrix pins ~> 3.2, which resolves to 3.2.5, and that version installs and passes on both Rails 8.0 and 8.1 — the rules had been hiding six working legs
• spec.files became a whitelist, so specs and dev files no longer ship (#226)