fix(ls): restore 100% coverage on latest after #9626

[manzoorwanijk]

Restores the global 100% coverage gate on latest, which broke after #9626.

filterLinkedStrategyEdges in lib/commands/ls.js skips dev edges on non-root packages — a guard added in #9095 to suppress false UNMET DEPENDENCY output in the linked strategy. #9626 fixed the root cause for store packages (they no longer load devDependencies as required edges), so the store-based test no longer produces a dev edge, leaving that branch unexercised.

Rather than ignore the line, this adds a regression test that genuinely exercises the guard: arborist still loads dev edges for a file:-linked transitive package, so listing one with --all under the linked strategy reaches the guard at depth > 0 and confirms its devDependency is suppressed instead of reported as UNMET DEPENDENCY. The full test suite passes at 100%.

This is the latest counterpart of #9636, which restored coverage on release/v11 via an istanbul ignore.

References

Follows up #9626