Let NodeCore fix non-canonical facedir itself

With commit 24e2e7b7, NodeCore has changed its rotation API.
It now automatically fixes "non-canonical" facedir values on
node update, and `spindata` is no longer.

init.lua

@@ -9,11 +9,8 @@ nc_extended_rotating.entity   = include("entity")   -- Depends on `utility`.
 nc_extended_rotating.registry = include("registry") -- Depends on `rotate` and `state` (late).
 nc_extended_rotating.state    = include("state")    -- Depends on `registry`, `rotate` and `utility`.
 
-do
 -- Do a quick check if we're using a compatible version of NodeCore.
-    local lens_def = minetest.registered_nodes["nc_optics:lens"]
+if not nodecore.param2_canonical then error("Requires NodeCore 24e2e7b7 or later") end
-    if not lens_def.spindata then error("Requires NodeCore 966ed012 or later") end
-end
 
 -------------------------------------
 -- Register Player Update Function --

state.lua

@@ -4,7 +4,6 @@ local math_round, minetest, vector
 local is_rightclick_filtered      = nc_extended_rotating.registry.is_rightclick_filtered;
 local is_rotatable                = nc_extended_rotating.registry.is_rotatable;
 local rotate_facedir              = nc_extended_rotating.rotate.rotate_facedir;
-local fix_rotatable_facedir       = nc_extended_rotating.utility.fix_rotatable_facedir;
 local rotation_vector_from_lookat = nc_extended_rotating.utility.rotation_vector_from_lookat;
 
 -- Distance at which we want to rotate by "pushing" on an edge.
@@ -66,7 +65,6 @@ local function calculate_rotating_state(player, data)
     state.invert = is_sneaking
 
     state.facedir = rotate_facedir(state.node.param2, state.axis, -degrees)
-    state.facedir = fix_rotatable_facedir(state.node, state.facedir)
     state.success = state.facedir and state.facedir ~= state.node.param2
 
     -- TODO: Until we have a way to display "rotation non-success", don't show rotation hint at all.

utility.lua

@@ -44,14 +44,4 @@ function utility.rotation_vector_from_lookat(node, pointed_thing, edge_distance)
         return b - math_abs(p) <= edge_distance and math_sign(p) or 0 end)
 end
 
--- NodeCore only has a couple of "canonical" orientations for its nodes.
--- This returns a canonical facedir equivalent to the one passed in.
-function utility.fix_rotatable_facedir(node, facedir)
-    local name = node and node.name or ""
-    local def  = minetest.registered_nodes[name]
-    if not def then return nil end
-    if not def.spindata then return facedir end
-    return def.spindata.equiv[facedir]
-end
-
 return utility