[gimp] app: make "gegl:introspect" an optional operation dependency.

[Jehan <jehanp src gnome org>]

commit 2cae9b9acf9da98c4c9990819ffbd5aabe23017e
Author: Jehan <jehan girinstud io>
Date:   Mon Dec 14 19:53:38 2020 +0100

    app: make "gegl:introspect" an optional operation dependency.
    
    Check at runtime for the operation availability and set the "Show Image
    Graph" action active depending on this check.
    
    This goes with discussions to make this operation optional with a
    runtime check for the tool `dot`.
    See: https://gitlab.gnome.org/GNOME/gegl/-/merge_requests/84

 app/actions/debug-actions.c | 6 ++++++
 app/sanity.c                | 1 -
 2 files changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/app/actions/debug-actions.c b/app/actions/debug-actions.c
index 6be4422b22..22ca38b15e 100644
--- a/app/actions/debug-actions.c
+++ b/app/actions/debug-actions.c
@@ -103,4 +103,10 @@ void
 debug_actions_update (GimpActionGroup *group,
                       gpointer         data)
 {
+#define SET_SENSITIVE(action,condition) \
+        gimp_action_group_set_action_sensitive (group, action, (condition) != 0)
+
+  SET_SENSITIVE ("debug-show-image-graph", gegl_has_operation ("gegl:introspect"));
+
+#undef SET_SENSITIVE
 }
diff --git a/app/sanity.c b/app/sanity.c
index 015801a396..6374ac1ad2 100644
--- a/app/sanity.c
+++ b/app/sanity.c
@@ -650,7 +650,6 @@ sanity_check_gegl_ops (void)
     "gegl:hue-chroma",
     "gegl:illusion",
     "gegl:image-gradient",
-    "gegl:introspect",
     "gegl:invert-gamma",
     "gegl:invert-linear",
     "gegl:lens-blur",