glm: fixup with other compilers than gcc >= 11
glm: fixup with other compilers than gcc >= 11

Amends 9464bf0ad6.  The flag isn't recognized on older gcc or clang.
https://hydra.nixos.org/eval/1756014?filter=glm.#tabs-still-fail

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs