fix: install vendored node_modules when using hardlinks

[eemelipa]

What does this PR do?

Fixes issue where vendored node_modules aren't installed with hardlink backend.

Vendored node_module is a folder inside an installed package which is called node_module. So the library has bundled some of their dependencies into the published package instead of specifying it in their package.json. For example

An npm package is called vendor-baz and it contains the following files:

x index.js
x package.json
x cjs/
x cjs/node_modules/
x cjs/node_modules/foo-dep/
x cjs/node_modules/foo-dep/index.js

The contents of cjs/node_modules/foo-dep/ is a vendored package.

• Documentation or TypeScript types (it's okay to leave the rest blank in this case)
• Code changes

How did you verify your code works?

I wrote automated tests

• I checked the lifetime of memory allocated to verify it's (1) freed and (2) only freed when it should be
• I included a test for the new code, or an existing test covers it
• JSValue used outside outside of the stack is either wrapped in a JSC.Strong or is JSValueProtect'ed
• I wrote TypeScript/JavaScript tests and they pass locally (bun-debug test test-file-name.test)

[eemelipa]

Similar testing approach as tests in test/cli/install/bun-install.test.ts and more specifically test case should prefer latest-tagged dependency

[dylan-conway]

TIL you can publish an npm package with a node_modules folder as long as it isn't top level

[dylan-conway]

Looks good to me. Will wait for CI to run

[dylan-conway]

We probably also want to do this for installWithSymlink, but it can be addressed in a future pr. I'm guessing there's a good chance top level node_modules will actually exist for local packages, so we would need to skip it

[dylan-conway]

Thank you