skipLibCheck is not working as intended on skipping modules-as-namespaces error #2909

Steps to reproduce

1. Start a plain new project
   a. "@typescript/native-preview": "^7.0.0-dev.20260225.1"
   b. "typescript": "6.0.0-beta"
   c. "gl-matrix": "3.4.3", or any package that has been treating modules as namespaces in types
2. Run npx tsgo --init to get the default tsconfig. Make sure "skipLibCheck" is set to true.
3. Add a src/main.ts. Run npx tsc --noEmit & npx tsgo --noEmit to see the difference.

// src/main.ts

import {} from 'gl-matrix';

Behavior with typescript@6.0

No error, as it should be.

Behavior with tsgo

Found 10 errors in the same file, starting at: node_modules/gl-matrix/index.d.ts:93

^All these errors is about modules-as-namespaces "mistakes", which are not skipped correctly by tsconfig.

By the way, it looks like skipLibCheck is not (yet) in the typescript playground. I think it is definitely a nice-to-have :)