fix(js): guard against undefined closest node in rehoistNodes (#34347)

## Current Behavior

When running `@nx/js:prune-lockfile` on a monorepo with transitive
dependencies that have multiple versions where neither version is
reachable from a direct dependency in package.json, the executor throws:

```
NX   An error occurred while creating pruned lockfile

Original error: Cannot read properties of undefined (reading 'name')

TypeError: Cannot read properties of undefined (reading 'name')
    at switchNodeToHoisted (node_modules/nx/src/plugins/js/lock-file/project-graph-pruning.js:165:31)
```

## Expected Behavior

The lockfile pruning should complete without crashing, even when some
transitive dependencies cannot be traced back to a direct dependency.

## Root Cause

In `rehoistNodes()`, when there are multiple nested nodes for a package,
the code finds the "closest" node by computing `pathLengthToIncoming()`
for each. However, when none of the nested nodes have a path to any
direct dependency in package.json, `pathLengthToIncoming()` returns
`undefined` for all of them. Since `undefined < Infinity` is `false` in
JavaScript, `closest` remains `undefined`, and then
`switchNodeToHoisted(undefined, ...)` crashes.

## Fix

Add a guard to only call `switchNodeToHoisted()` when a closest node was
actually found:

```typescript
if (closest) {
  switchNodeToHoisted(closest, builder, invBuilder);
}
```

This allows the pruning to continue - the nested nodes simply won't be
rehoisted if no closest node can be determined.

## Related Issue

Fixes #34322

## Test Added

Added a unit test that verifies `rehoistNodes()` doesn't crash when
nested nodes have no path to package.json dependencies.

(cherry picked from commit b46de60)

Author: kaigritun

packages/nx/src/plugins/js/lock-file/project-graph-pruning.spec.ts

@@ -424,6 +424,48 @@ describe('project-graph-pruning', () => {
         '4.17.20'
       );
     });
+
+    it('should not crash when nested nodes have no path to package.json deps', () => {
+      // This tests the fix for https://github.com/nrwl/nx/issues/34322
+      // When transitive dependencies have multiple versions where neither version
+      // is reachable from a direct dependency, the code should not crash.
+
+      // Setup: Add multiple nested versions that are NOT in packageJsonDeps
+      builder.addExternalNode({
+        type: 'npm',
+        name: 'npm:lodash@4.17.20',
+        data: {
+          packageName: 'lodash',
+          version: '4.17.20',
+        },
+      });
+      builder.addExternalNode({
+        type: 'npm',
+        name: 'npm:lodash@4.17.19',
+        data: {
+          packageName: 'lodash',
+          version: '4.17.19',
+        },
+      });
+      // Connect them as nested dependencies
+      builder.addStaticDependency('npm:lodash@4.17.20', 'npm:lodash@4.17.19');
+
+      // packageJsonDeps does NOT include lodash, so pathLengthToIncoming
+      // will return undefined for both nested nodes
+      const packageJsonDeps = {
+        typescript: '5.0.0',
+      };
+
+      // Should NOT throw "Cannot read properties of undefined (reading 'name')"
+      expect(() => rehoistNodes(graph, packageJsonDeps, builder)).not.toThrow();
+
+      const result = builder.getUpdatedProjectGraph();
+      // Nested nodes should remain as-is (not rehoisted)
+      expect(result.externalNodes?.['npm:lodash@4.17.20']).toBeDefined();
+      expect(result.externalNodes?.['npm:lodash@4.17.19']).toBeDefined();
+      // npm:lodash should NOT be created since we couldn't determine which to hoist
+      expect(result.externalNodes?.['npm:lodash']).toBeUndefined();
+    });
   });
 
   describe('pruneProjectGraph', () => {

packages/nx/src/plugins/js/lock-file/project-graph-pruning.ts

@@ -247,7 +247,9 @@ export function rehoistNodes(
           closest = node;
         }
       });
-      switchNodeToHoisted(closest, builder, invBuilder);
+      if (closest) {
+        switchNodeToHoisted(closest, builder, invBuilder);
+      }
     }
   });
 }