Cycles: Remove Use Tiling option

Always enforce tiling of some size, up to the 8k tile size.

Rendering very big images without tiles have a lot of challenges.
While solving those challenges is not impossible, it does not seem to
be a practical time investment.

The internals of the way how Cycles work, including Cycles Standalone
is not affected by this change.

A possible downside is that path guiding might not work exactly how one
would expect it to due to lack of information sharing across multiple
tiles. This is something that never worked nicely, and camera animation
and border render has the same issues, so it is not considered a stopper
for this change.

Fixes #145900

Co-authored-by: Brecht Van Lommel <brecht@blender.org>

Pull Request: https://projects.blender.org/blender/blender/pulls/146031

scripts/presets/cycles/performance/Default.py

@@ -8,5 +8,4 @@ cycles.debug_use_spatial_splits = False
 cycles.debug_use_compact_bvh = False
 cycles.debug_use_hair_bvh = True
 cycles.debug_bvh_time_steps = 0
-cycles.use_auto_tile = True
 cycles.tile_size = 2048

scripts/presets/cycles/performance/Faster_Render.py

@@ -8,5 +8,4 @@ cycles.debug_use_spatial_splits = True
 cycles.debug_use_compact_bvh = False
 cycles.debug_use_hair_bvh = True
 cycles.debug_bvh_time_steps = 2
-cycles.use_auto_tile = True
 cycles.tile_size = 2048

scripts/presets/cycles/performance/Lower_Memory.py

@@ -8,5 +8,4 @@ cycles.debug_use_spatial_splits = False
 cycles.debug_use_compact_bvh = True
 cycles.debug_use_hair_bvh = True
 cycles.debug_bvh_time_steps = 0
-cycles.use_auto_tile = True
 cycles.tile_size = 512