exclude macos from bnb upgrade

Author: Ali Alshaarawy

requirements/fabric/strategies.txt

@@ -6,4 +6,5 @@
 # note: is a bug around 0.10 with `MPS_Accelerator must implement all abstract methods`
 #  shall be resolved by https://github.com/microsoft/DeepSpeed/issues/4372
 deepspeed >=0.8.2, <=0.9.3; platform_system != "Windows" and platform_system != "Darwin"  # strict
-bitsandbytes >=0.44.0,<0.44.2
+bitsandbytes >=0.44.0,<0.44.2; sys_platform == 'linux' or sys_platform == 'win32'
+bitsandbytes >=0.42.0,<0.43.0 ; sys_platform == 'darwin'

requirements/pytorch/extra.txt

@@ -8,4 +8,5 @@ hydra-core >=1.2.0, <1.4.0
 jsonargparse[signatures] >=4.27.7, <4.28.0
 rich >=12.3.0, <13.6.0
 tensorboardX >=2.2, <2.7.0  # min version is set by torch.onnx missing attribute
-bitsandbytes >=0.44.0,<0.44.2
+bitsandbytes >=0.44.0,<0.44.2; sys_platform == 'linux' or sys_platform == 'win32'
+bitsandbytes >=0.42.0,<0.43.0 ; sys_platform == 'darwin'

src/lightning/fabric/plugins/precision/bitsandbytes.py

@@ -39,7 +39,7 @@
 
 log = logging.getLogger(__name__)
 
-_BITSANDBYTES_AVAILABLE = RequirementCache("bitsandbytes>=0.44.0")
+_BITSANDBYTES_AVAILABLE = RequirementCache("bitsandbytes>=0.42.0")
 
 
 class BitsandbytesPrecision(Precision):