The CSS link tests keep their node_modules fixture

linksTestFixtures/node_modules/foo/package.json is hand-written input for
the `node module resolving` and `node module subfolder resolving` tests in
links.test.ts, which is why the fixture directory carries its own
`!/node_modules`. Without it both fail to find any link.

Co-authored-by: Hanzo Dev <[email protected]>

extensions/css-language-features/server/test/linksTestFixtures/node_modules/foo/package.json

@@ -0,0 +1 @@
+{}