fix(ci): don't error on optional deps in the lockfile

[wraithgar]

We build a virtual tree from the lockfile before we build the ideal tree so that we can compare the two and error if package.json differs from what was used to build the lockfile.

The virtual tree includes optional deps in it that would otherwise be ignored when building the ideal tree. In order not to have npm ci fail in this situation we need to build the virtual tree separately, and start clean when building the ideal tree.

This also brings in a few linting fixups.

[wraithgar]

~/D/s/doc-kit $ node /Users/gar/Development/npm/cli/branches/gar_optional-ci ci

added 634 packages, and audited 642 packages in 9s

2 vulnerabilities (1 moderate, 1 high)

To address all issues, run:
  npm audit fix

Run `npm audit` for details.
~/D/s/doc-kit $ npm ci
npm error code EBADPLATFORM
npm error notsup Unsupported platform for @unrs/resolver-binding-android-arm-eabi@1.9.2: wanted {"os":"android","cpu":"arm"} (current: {"os":"darwin","cpu":"arm64"})
npm error notsup Valid os:   android
npm error notsup Actual os:  darwin
npm error notsup Valid cpu:  arm
npm error notsup Actual cpu: arm64
npm error A complete log of this run can be found in: /Users/gar/.npm/_logs/2026-03-09T16_44_04_539Z-debug-0.log