Try via platform_system instead of sys_platform

Author: agriyakhetarpal

pyproject.toml

@@ -14,10 +14,10 @@ requires-python = ">=3.9"
 dependencies = [
     'asciitree',
     'numpy>=1.23',
-    'fasteners; sys_platform != "emscripten"',
+    'fasteners; platform_system != "Emscripten"',
     'numcodecs>=0.10.0',
-    'numcodecs[msgpack]>=0.10.0; sys_platform == "emscripten"',  # TODO: can be removed
-    'msgpack; sys_platform == "emscripten"',
+    'numcodecs[msgpack]>=0.10.0; platform_system == "Emscripten"',  # TODO: can be removed
+    'msgpack; platform_system == "Emscripten"',
 ]
 dynamic = [
   "version",