Cleanup: Rename #if GPU_USE_PY_REFERENCES to #ifndef GPU_NO_USE_PY_REFERENCES

This is safer for incremental build.

And there was already a macro `GPU_USE_PY_REFERENCES` used elsewhere.

source/blender/gpu/GPU_common.h

@@ -24,7 +24,7 @@
 #pragma once
 
 #define PROGRAM_NO_OPTI 0
-#define USE_PY_REFERENCES 1
+//#define GPU_NO_USE_PY_REFERENCES
 
 #if defined(NDEBUG)
 #  define TRUST_NO_ONE 0

source/blender/gpu/GPU_framebuffer.h

@@ -209,7 +209,7 @@ void GPU_framebuffer_recursive_downsample(GPUFrameBuffer *fb,
                                           void (*callback)(void *userData, int level),
                                           void *userData);
 
-#if USE_PY_REFERENCES
+#ifndef GPU_NO_USE_PY_REFERENCES
 void **GPU_framebuffer_py_reference_get(GPUFrameBuffer *gpu_fb);
 void GPU_framebuffer_py_reference_set(GPUFrameBuffer *gpu_fb, void **py_ref);
 #endif

source/blender/gpu/GPU_texture.h

@@ -270,7 +270,7 @@ bool GPU_texture_depth(const GPUTexture *tex);
 bool GPU_texture_stencil(const GPUTexture *tex);
 bool GPU_texture_integer(const GPUTexture *tex);
 
-#if USE_PY_REFERENCES
+#ifndef GPU_NO_USE_PY_REFERENCES
 void **GPU_texture_py_reference_get(GPUTexture *tex);
 void GPU_texture_py_reference_set(GPUTexture *tex, void **py_ref);
 #endif

source/blender/gpu/intern/gpu_framebuffer.cc

@@ -72,7 +72,7 @@ FrameBuffer::~FrameBuffer()
     }
   }
 
-#if USE_PY_REFERENCES
+#ifndef GPU_NO_USE_PY_REFERENCES
   if (this->py_ref) {
     *this->py_ref = nullptr;
   }
@@ -479,7 +479,7 @@ void GPU_framebuffer_recursive_downsample(GPUFrameBuffer *gpu_fb,
   unwrap(gpu_fb)->recursive_downsample(max_lvl, callback, userData);
 }
 
-#if USE_PY_REFERENCES
+#ifndef GPU_NO_USE_PY_REFERENCES
 void **GPU_framebuffer_py_reference_get(GPUFrameBuffer *gpu_fb)
 {
   return unwrap(gpu_fb)->py_ref;

source/blender/gpu/intern/gpu_framebuffer_private.hh

@@ -100,7 +100,7 @@ class FrameBuffer {
   bool scissor_test_ = false;
   bool dirty_state_ = true;
 
-#if USE_PY_REFERENCES
+#ifndef GPU_NO_USE_PY_REFERENCES
  public:
   /**
    * Reference of a pointer that needs to be cleaned when deallocating the frame-buffer.

source/blender/gpu/intern/gpu_texture.cc

@@ -61,7 +61,7 @@ Texture::~Texture()
     }
   }
 
-#if USE_PY_REFERENCES
+#ifndef GPU_NO_USE_PY_REFERENCES
   if (this->py_ref) {
     *this->py_ref = nullptr;
   }
@@ -587,7 +587,7 @@ bool GPU_texture_array(const GPUTexture *tex)
   return (reinterpret_cast<const Texture *>(tex)->type_get() & GPU_TEXTURE_ARRAY) != 0;
 }
 
-#if USE_PY_REFERENCES
+#ifndef GPU_NO_USE_PY_REFERENCES
 void **GPU_texture_py_reference_get(GPUTexture *tex)
 {
   return unwrap(tex)->py_ref;

source/blender/gpu/intern/gpu_texture_private.hh

@@ -80,7 +80,7 @@ class Texture {
   int refcount = 1;
   /** Width & Height (of source data), optional. */
   int src_w = 0, src_h = 0;
-#if USE_PY_REFERENCES
+#ifndef GPU_NO_USE_PY_REFERENCES
   /**
    * Reference of a pointer that needs to be cleaned when deallocating the texture.
    * Points to #BPyGPUTexture.tex