PR #23441: Up HERMETIC_CUDA_VERSION default value to 12.6.3

Imported from GitHub PR #23441

Copybara import of the project:

--
caacac1 by Shraiysh Vaishay <[email protected]>:

Up HERMETIC_CUDA_VERSION default value to 12.6.3

Merging this change closes #23441

COPYBARA_INTEGRATE_REVIEW=#23441 from shraiysh:up-hermetic-cuda-default caacac1
PiperOrigin-RevId: 735448478

Author: shraiysh

tensorflow.bazelrc

@@ -162,7 +162,7 @@ build:cuda --repo_env TF_NEED_CUDA=1
 build:cuda --crosstool_top=@local_config_cuda//crosstool:toolchain
 build:cuda --@local_config_cuda//:enable_cuda
 # Default CUDA and CUDNN versions.
-build:cuda --repo_env=HERMETIC_CUDA_VERSION="12.5.1"
+build:cuda --repo_env=HERMETIC_CUDA_VERSION="12.6.3"
 build:cuda --repo_env=HERMETIC_CUDNN_VERSION="9.3.0"
 # This flag is needed to include CUDA libraries.
 build:cuda --@local_config_cuda//cuda:include_cuda_libs=true
@@ -193,7 +193,7 @@ build:cuda_clang --linkopt="-lm"
 
 # Set up compilation CUDA version and paths and use the CUDA Clang toolchain.
 build:cuda_clang_official --config=cuda_clang
-build:cuda_clang_official --repo_env=HERMETIC_CUDA_VERSION="12.5.1"
+build:cuda_clang_official --repo_env=HERMETIC_CUDA_VERSION="12.6.3"
 build:cuda_clang_official --repo_env=HERMETIC_CUDNN_VERSION="9.3.0"
 build:cuda_clang_official --action_env=CLANG_CUDA_COMPILER_PATH="/usr/lib/llvm-18/bin/clang"
 build:cuda_clang_official --crosstool_top="@local_config_cuda//crosstool:toolchain"