[BUG] v11.6.1 fails to install optionalDependencies of inner package (even if build works)

Is there an existing issue for this?

• I have searched the existing issues

This issue exists in the latest npm version

• I am using the latest npm

Current Behavior

If we have two packages, for example,
package child:

{
  "name": "child-package-repro",
  "version": "1.0.3",
  "optionalDependencies": {
    "pg": "^8.16.3"
  }
}

and package parent:

{
  "name": "parent-package",
  "version": "1.0.0",
  "dependencies": {
    "child-package-repro": "1.0.3"
  }
}

When npm install on the parent package, if it contains a package-lock.json (generated with previous versions) with the optionalDependency (which is marked as optional) it will completely remove the pg dependency. More over, this worked fine in v11.6.0 and before.

Expected Behavior

The optional dependency pg should be installed in parent/node_modules/child-package/node_modules/pg (or hoisted to parent/node_modules/pg).

Steps To Reproduce

With this package: https://github.com/otaviojacobi/npm-cli-repro

1. Inside the parent directory run:
2. npm install
3. npm ls pg will result with:

❯ npm ls pg
parent-package@1.0.0 /home/repro/parent
└── (empty)

While if you install with any previous version of npm (11.6.0 or lower):

❯ npm ls pg
parent-package@1.0.0 /home/repro/parent
└─┬ child-package-repro@1.0.3
  └─┬ pg@8.16.3
    └─┬ pg-pool@3.10.1
      └── pg@8.16.3 deduped

My understanding is that this issue is coming from https://github.com/npm/cli/pull/8579 which is causing a optionalDependency to be removed from the final tree.

Environment

No response

Start with the linked npm-cli-repro repository: run npm install in the parent directory and compare npm ls pg with npm 11.6.0 and earlier. Read the behavior introduced by npm/cli pull request 8579, then verify that the child package's optional pg dependency remains installed or hoisted and appears in npm ls pg.