Fix download and extraction of NINJA_SYNTAX

* With this Dockerfile:
  FROM oraclelinux:10
  RUN dnf install git
  COPY . /mx
  ENV PATH=/mx:$PATH
  WORKDIR /mx
  RUN mx version
  RUN ls -la ~/.mx/cache/NINJA_SYNTAX*
  RUN ls -la ~/.mx/cache/NINJA_SYNTAX*/*
  RUN ls -la ~/.mx/cache/NINJA_SYNTAX*/*/*
  RUN mx path --download NINJA_SYNTAX
  RUN ls -la ~/.mx/cache/NINJA_SYNTAX*
  RUN ls -la ~/.mx/cache/NINJA_SYNTAX*/*/*
* Before this commit it's clear that ~/.mx/cache/NINJA_SYNTAX*/*/* is empty
  and remains empty even after `mx path --download NINJA_SYNTAX`.
* After this commit, NINJA_SYNTAX is downloaded as soon as NinjaProject.resolveDeps is called.

Author: eregon

src/mx/_impl/mx_native.py

@@ -683,7 +683,7 @@ def _ninja_deps(cls):  # pylint: disable=no-self-argument
         except ImportError:
             dep = mx.library('NINJA_SYNTAX')
             deps.append(dep)
-            module_path = os.path.join(dep.get_path(False), f'ninja_syntax-{dep.version}')
+            module_path = os.path.join(dep.get_path(True), f'ninja_syntax-{dep.version}')
             mx_util.ensure_dir_exists(module_path)  # otherwise, import machinery will ignore it
             sys.path.append(module_path)