compile error: gtd-enum-types.h: No such file or directory

While working on reproducible builds for openSUSE, I found that our endeavour-42.0 package fails to build in a 1-core VM.

To Reproduce on Debian or openSUSE do:

osc co openSUSE:Factory/endeavour && cd $_
osc build --vm-type=kvm -j1 --clean --noservice standard

This probably comes from src/meson.build that defines

enum_types = 'gtd-enum-types'

gtd_enum_types = gnome.mkenums(
  enum_types,
     sources: enum_headers,
  c_template: enum_types + '.c.template',
  h_template: enum_types + '.h.template'
)

and probably does not list it as a dependency in some places that include src/endeavour.h e.g. when compiling via make -j1 src/plugins/libplugins.a.p/all-tasks-panel_all-tasks-panel-plugin.c.o it fails with

../src/endeavour.h:24:10: fatal error: gtd-enum-types.h: No such file or directory
   24 | #include "gtd-enum-types.h"
      |          ^~~~~~~~~~~~~~~~~~
compilation terminated.