Fix deprecated alpha / use_texture_alpha use

functions.lua

@@ -463,6 +463,7 @@ function default.register_mesepost(name, def)
 		},
 		paramtype = "light",
 		tiles = {def.texture, def.texture, post_texture_dark, post_texture_dark, post_texture, post_texture},
+		use_texture_alpha = "opaque",
 		light_source = default.LIGHT_MAX,
 		sunlight_propagates = true,
 		is_ground_content = false,

nodes.lua

@@ -2213,7 +2213,7 @@ minetest.register_node("default:water_source", {
 			},
 		},
 	},
-	alpha = 191,
+	use_texture_alpha = "blend",
 	paramtype = "light",
 	walkable = false,
 	pointable = false,
@@ -2258,7 +2258,7 @@ minetest.register_node("default:water_flowing", {
 			},
 		},
 	},
-	alpha = 191,
+	use_texture_alpha = "blend",
 	paramtype = "light",
 	paramtype2 = "flowingliquid",
 	walkable = false,
@@ -2304,7 +2304,7 @@ minetest.register_node("default:river_water_source", {
 			},
 		},
 	},
-	alpha = 160,
+	use_texture_alpha = "blend",
 	paramtype = "light",
 	walkable = false,
 	pointable = false,
@@ -2354,7 +2354,7 @@ minetest.register_node("default:river_water_flowing", {
 			},
 		},
 	},
-	alpha = 160,
+	use_texture_alpha = "blend",
 	paramtype = "light",
 	paramtype2 = "flowingliquid",
 	walkable = false,
@@ -2578,6 +2578,7 @@ local function register_sign(material, desc, def)
 		sunlight_propagates = true,
 		is_ground_content = false,
 		walkable = false,
+		use_texture_alpha = "opaque",
 		node_box = {
 			type = "wallmounted",
 			wall_top    = {-0.4375, 0.4375, -0.3125, 0.4375, 0.5, 0.3125},

torch.lua

@@ -29,6 +29,7 @@ minetest.register_node("default:torch", {
 		    name = "default_torch_on_floor_animated.png",
 		    animation = {type = "vertical_frames", aspect_w = 16, aspect_h = 16, length = 3.3}
 	}},
+	use_texture_alpha = "clip",
 	paramtype = "light",
 	paramtype2 = "wallmounted",
 	sunlight_propagates = true,
@@ -81,6 +82,7 @@ minetest.register_node("default:torch_wall", {
 		    name = "default_torch_on_floor_animated.png",
 		    animation = {type = "vertical_frames", aspect_w = 16, aspect_h = 16, length = 3.3}
 	}},
+	use_texture_alpha = "clip",
 	paramtype = "light",
 	paramtype2 = "wallmounted",
 	sunlight_propagates = true,
@@ -105,6 +107,7 @@ minetest.register_node("default:torch_ceiling", {
 		    name = "default_torch_on_floor_animated.png",
 		    animation = {type = "vertical_frames", aspect_w = 16, aspect_h = 16, length = 3.3}
 	}},
+	use_texture_alpha = "clip",
 	paramtype = "light",
 	paramtype2 = "wallmounted",
 	sunlight_propagates = true,