[flutter_tools] Fix VS Code package.json path on macOS with case-sensitive file system (#163409)

This PR corrects the path to VS Code's `package.json` in `flutter
doctor` for macOS with a case-sensitive file system. The correct
directory name is `Resources`, but the existing code incorrectly uses
`resources`.

On a case-insensitive file system (the macOS default), this issue does
not appear. However, on a case-sensitive file system, `flutter doctor`
fails to detect the VS Code version correctly.

Fixes #163408.

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packages/flutter_tools/lib/src/vscode/vscode.dart

@@ -71,7 +71,7 @@ class VsCode {
   }) {
     final String packageJsonPath = fileSystem.path.join(
       installPath,
-      'resources',
+      'Resources',
       'app',
       'package.json',
     );

packages/flutter_tools/test/general.shard/vscode/vscode_test.dart

@@ -51,7 +51,7 @@ void main() {
   testWithoutContext('VsCode.fromDirectory does not crash when packages.json is malformed', () {
     final MemoryFileSystem fileSystem = MemoryFileSystem.test();
     // Create invalid JSON file.
-    fileSystem.file(fileSystem.path.join('', 'resources', 'app', 'package.json'))
+    fileSystem.file(fileSystem.path.join('', 'Resources', 'app', 'package.json'))
       ..createSync(recursive: true)
       ..writeAsStringSync('{');