devel/cmake: update to 3.26.1, latest upstream

See release notes at
https://cmake.org/cmake/help/v3.26/release/3.26.html

Some "while we're at it" changes:

• remove obsolete patch, reported by: diizzy (PR 270337)
• set LOCALSTATEDIR to /var (PR 267748)

Thanks antoine@ for the exp-run.

PR: 270491 270337 267748