Describe the bug
If the nasm language is enabled in a project, the rewriter refuses to operate on it.

This bisects to a6c4a4d; cc @dcbaker.

To Reproduce
Ensure NASM is installed.

project('a', 'nasm', license: 'MIT')

Then run e.g. meson rewrite kwargs info project / or meson rewrite kwargs set project / license BSD.

meson.build:1:0: ERROR: ASM Compiler nasm does not support building for None CPU family.

Expected behavior
The command succeeds.

system parameters

• Is this a cross build or just a plain native build (for the same computer)?
  native

• what operating system (e.g. MacOS Catalina, Windows 10, CentOS 8.0, Ubuntu 18.04, etc.)
  Fedora 43

• what Python version are you using e.g. 3.8.0
  3.14.0

• what meson --version
  1.10.0

• what ninja --version if it's a Ninja build
  1.13.1