[Python] Remove --parallel from cmake --build command in setup.py

Causes problems due to unlimited parallel compilation with make.
Better let this be controlled by setting CMAKE_BUILD_PARALLEL_LEVEL
environment variable, which only works if --parallel option is not
passed in the command line.

https://cmake.org/cmake/help/latest/envvar/CMAKE_BUILD_PARALLEL_LEVEL.html

Fixes: xrootd#2356

bindings/python/setup.py

@@ -118,7 +118,7 @@ def build_extensions(self):
                 os.makedirs(self.build_temp)
 
             check_call([cmake, ext.src, '-B', self.build_temp] + cmake_args)
-            check_call([cmake, '--build', self.build_temp, '--parallel'])
+            check_call([cmake, '--build', self.build_temp])
 
 version = get_version()
 

setup.py

@@ -87,7 +87,7 @@ def build_extensions(self):
                 os.makedirs(self.build_temp)
 
             check_call([cmake, ext.src, '-B', self.build_temp] + cmake_args)
-            check_call([cmake, '--build', self.build_temp, '--parallel'])
+            check_call([cmake, '--build', self.build_temp])
 
 version = get_version()