Blender Git Loki

Fix T73763: Laggy when zooming a node editor with International Fonts

Two main reasons for the lag:
- Allocation of memory with transfer to GPU.
- BLF_cache_clear();

The (partial) solution is to avoid memory allocating in some setups
through the `GPU_texture_clear`.

Differential Revision: https://developer.blender.org/D6837