Invoke correct CMake when building tsan libdispatch

This should address a build failure on TSAN - libdispatch Linux bots

Addresses rdar://88339546

Author: edymtt

utils/swift_build_support/swift_build_support/products/tsan_libdispatch.py

@@ -54,7 +54,7 @@ def build(self, host_target):
         clangxx = join_path(toolchain_path, 'bin', 'clang++')
 
         config_cmd = [
-            'cmake',
+            self.toolchain.cmake,
             '-GNinja',
             '-DCMAKE_PREFIX_PATH=%s' % toolchain_path,
             '-DCMAKE_C_COMPILER=%s' % clang,