Bind missing FLAG_DISABLE_Z enum value in ParticlesMaterial

Fixes #29419.

(cherry picked from commit a3462c97adc63461b12462d57c75a67ce54cecfd)

doc/classes/ParticlesMaterial.xml

@@ -214,14 +214,19 @@
 			Use with [method set_param], [method set_param_randomness], and [method set_param_texture] to set animation offset properties.
 		</constant>
 		<constant name="PARAM_MAX" value="12" enum="Parameter">
+			Represents the size of the [enum Parameter] enum.
 		</constant>
 		<constant name="FLAG_ALIGN_Y_TO_VELOCITY" value="0" enum="Flags">
 			Use with [method set_flag] to set [member flag_align_y].
 		</constant>
 		<constant name="FLAG_ROTATE_Y" value="1" enum="Flags">
-			Use with [method set_flag] to set [member flag_rotate_y]
+			Use with [method set_flag] to set [member flag_rotate_y].
+		</constant>
+		<constant name="FLAG_DISABLE_Z" value="2" enum="Flags">
+			Use with [method set_flag] to set [member flag_disable_z].
 		</constant>
 		<constant name="FLAG_MAX" value="3" enum="Flags">
+			Represents the size of the [enum Flags] enum.
 		</constant>
 		<constant name="EMISSION_SHAPE_POINT" value="0" enum="EmissionShape">
 			All particles will be emitted from a single point.

scene/resources/particles_material.cpp

@@ -1187,6 +1187,7 @@ void ParticlesMaterial::_bind_methods() {
 
 	BIND_ENUM_CONSTANT(FLAG_ALIGN_Y_TO_VELOCITY);
 	BIND_ENUM_CONSTANT(FLAG_ROTATE_Y);
+	BIND_ENUM_CONSTANT(FLAG_DISABLE_Z);
 	BIND_ENUM_CONSTANT(FLAG_MAX);
 
 	BIND_ENUM_CONSTANT(EMISSION_SHAPE_POINT);