Update test-requirements.txt

Author: xrmx

opentelemetry-sdk/test-requirements.txt

@@ -5,7 +5,7 @@ importlib-metadata==6.11.0
 iniconfig==2.0.0
 packaging==24.0
 pluggy==1.5.0
-psutil==5.9.6
+psutil==5.9.6; sys_platform == 'win32'
 py-cpuinfo==9.0.0
 pytest==7.4.4
 tomli==2.0.1