fix: Pin flashinfer-python to 0.6.8.post1 (#679)

Signed-off-by: Charlie Truong <chtruong@nvidia.com>

Author: chtruong814

pyproject.toml

@@ -67,7 +67,7 @@ dependencies = [
     "wandb",
     "webdataset>=0.2.86",
     "nvidia-pytriton ; platform_system != 'Darwin' ",
-    "flashinfer-python>=0.2.5 ; platform_system != 'Darwin'",
+    "flashinfer-python==0.6.8.post1 ; platform_system != 'Darwin'",
     "Pillow ; platform_system != 'Darwin' and platform_machine != 'aarch64'",
     "decord ; platform_system != 'Darwin' and platform_machine != 'aarch64'",
     "pyparsing>2.0.2",
@@ -144,7 +144,7 @@ override-dependencies = [
     "transformer-engine[pytorch]>=2.14.0a0,<2.17.0",
     "open-clip-torch>=3.2.0",
     "megatron-energon[av-decode]>=6.0,<7.dev0",
-    "flashinfer-python>=0.3.0,<0.4.0",
+    "flashinfer-python==0.6.8.post1",
     "datasets>=3.3.0",
     "flash-linear-attention>=0.3.0,<0.4.dev0",
     "patchelf; sys_platform=='never'",