stack/monitor: backport a fix for python-dateutil setup_requires

This is equivalent to 6e491a6b (ensure working version o
setuptools_scm for python-dateutil, 2021-03-30)

stack/monitor/buildout.cfg

@@ -24,6 +24,11 @@ download-only = true
 url = ${:_profile_base_location_}/${:_update_hash_filename_}
 mode = 0644
 
+[python-dateutil]
+recipe = zc.recipe.egg:custom
+egg = ${:_buildout_section_name_}
+setup-eggs = setuptools_scm
+
 [monitor-template-script]
 <= monitor-download-base
 url = ${:_profile_base_location_}/scripts/${:filename}
@@ -39,6 +44,7 @@ eggs =
   plone.recipe.command
   collective.recipe.template
   cns.recipe.symlink
+  ${python-dateutil:egg}
   slapos.toolbox
   slapos.core