Lower MSRV to keep compatibility with RHEL-based distros (Rocky Linux 8)

RHEL-based distros like Rocky Linux 8 ship Rust toolchains that are roughly 6 months behind the latest stable release. This is just how the RHEL ecosystem works, packages go through validation before being distributed. As of May 2026: nextest MSRV: 1.91 Rust on Rocky Linux 8: 1.88 Next expected update: Rocky Linux is expected to bump to ~1.92 around mid may, and then the next update would be around November 2026 So users on Rocky Linux 8 (and RHEL 8, AlmaLinux 8, etc.) simply can't use nextest without manually installing Rust via rustup, which isn't always an option in enterprise or CI environments with strict toolchain policies. Would it be possible to either lower the MSRV back to 1.88, or adopt a more conservative bump policy that keeps a ~6 month buffer behind the latest stable release? That would be enough to stay compatible with RHEL-family distros without really holding back development.