GH-179 Function Call Target pin no longer autowired

There are situations where a function signature may contain multiple pins
that would match the autowire criteria, and we should automatically skip
the `Target` pin because its generally never intended to be what will be
autowired.

src/editor/graph/graph_edit.cpp

@@ -622,6 +622,10 @@ void OrchestratorGraphEdit::_attempt_autowire(const Ref<OScriptNode>& p_new_node
         if (!pin.is_valid() || pin->get_flags().has_flag(OScriptNodePin::Flags::HIDDEN))
             continue;
 
+        // Skip pins that are specifically flagged as non-autowirable
+        if (pin->get_flags().has_flag(OScriptNodePin::Flags::NO_AUTOWIRE))
+            continue;
+
         // If pin direction matches drag, skip
         if (_drag_context.get_direction() == pin->get_direction())
             continue;

src/script/node_pin.h

@@ -71,6 +71,7 @@ class OScriptNodePin : public Resource
         SHOW_LABEL      = 1 << 9,   //! Label should be shown, always
         HIDE_LABEL      = 1 << 10,  //! Label should be hidden, always
         NO_CAPITALIZE   = 1 << 11,  //! Label is not capitalized
+        NO_AUTOWIRE     = 1 << 12,  //! Prevents being autowired
         CONST           = 1 << 20,  //! Represents a "const" data port
         REFERENCE       = 1 << 21,  //! Represents a "reference" data port
         OBJECT          = 1 << 22,  //! Refers to an object type

src/script/nodes/functions/call_function.cpp

@@ -253,7 +253,7 @@ void OScriptNodeCallFunction::_create_pins_for_method(const MethodInfo& p_method
     {
         Variant::Type target_type = _reference.target_type != Variant::NIL ? _reference.target_type : Variant::OBJECT;
         Ref<OScriptNodePin> target = create_pin(PD_Input, "target", target_type);
-        target->set_flags(OScriptNodePin::Flags::DATA);
+        target->set_flags(OScriptNodePin::Flags::DATA | OScriptNodePin::Flags::NO_AUTOWIRE);
         if (_reference.target_type == Variant::NIL)
         {
             if (_function_flags.has_flag(FF_IS_SELF))