test: fix ngcc integration tests in windows (#30297)

```
//packages/compiler-cli/ngcc/test:integration
```

Partially addresses #29785

PR Close #30297

packages/compiler-cli/ngcc/src/file_system/node_js_file_system.ts

@@ -23,7 +23,7 @@ export class NodeJSFileSystem implements FileSystem {
   readdir(path: AbsoluteFsPath): PathSegment[] { return fs.readdirSync(path) as PathSegment[]; }
   lstat(path: AbsoluteFsPath): fs.Stats { return fs.lstatSync(path); }
   stat(path: AbsoluteFsPath): fs.Stats { return fs.statSync(path); }
-  pwd() { return AbsoluteFsPath.fromUnchecked(process.cwd()); }
+  pwd() { return AbsoluteFsPath.from(process.cwd()); }
   copyFile(from: AbsoluteFsPath, to: AbsoluteFsPath): void { cp(from, to); }
   moveFile(from: AbsoluteFsPath, to: AbsoluteFsPath): void { mv(from, to); }
   ensureDir(path: AbsoluteFsPath): void { mkdir('-p', path); }

packages/compiler-cli/ngcc/src/packages/entry_point_finder.ts

@@ -92,7 +92,7 @@ export class EntryPointFinder {
             entryPoints.push(...this.getEntryPointsForPackage(packagePath));
 
             // Also check for any nested node_modules in this package
-            const nestedNodeModulesPath = AbsoluteFsPath.resolve(packagePath, 'node_modules');
+            const nestedNodeModulesPath = AbsoluteFsPath.join(packagePath, 'node_modules');
             if (this.fs.exists(nestedNodeModulesPath)) {
               entryPoints.push(...this.walkDirectoryForEntryPoints(nestedNodeModulesPath));
             }