deps: Update dependency pytorch to >=2.9.1 (#576)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

pixi.lock

@@ -148,7 +148,7 @@ numpy = "=1.24.1"
 # Backends that can run on CPU-only hosts
 # Note: JAX and PyTorch will install CPU variants.
 [tool.pixi.feature.backends.dependencies]
-pytorch = ">=2.7.1"
+pytorch = ">=2.9.1"
 dask-core = ">=2025.12.0" # No distributed, tornado, etc.
 sparse = ">=0.17.0"
 
@@ -179,7 +179,7 @@ system-requirements = { cuda = "12" }
 cupy = ">=13.6.0"
 # JAX 0.6.2 and 0.7.0 segfault on CUDA
 jaxlib = { version = ">=0.6.0,!=0.6.2,!=0.7.0", build = "cuda12*" }
-pytorch = { version = ">=2.7.1", build = "cuda12*" }
+pytorch = { version = ">=2.9.1", build = "cuda12*" }
 
 [tool.pixi.feature.cuda-backends.target.osx-64.dependencies]
 # cupy = "*"  # unavailable
@@ -194,7 +194,7 @@ pytorch = { version = ">=2.7.1", build = "cuda12*" }
 [tool.pixi.feature.cuda-backends.target.win-64.dependencies]
 cupy = ">=13.6.0"
 # jaxlib = { version = "*", build = "cuda12*" }  # unavailable
-pytorch = { version = ">=2.8.0", build = "cuda12*" }
+pytorch = { version = ">=2.9.1", build = "cuda12*" }
 
 [tool.pixi.feature.nogil.dependencies]
 python-freethreading = "~=3.13.0"