fix: lint backend and doc files

[drbh]

This PR simply fixes linting issues with recent changes on main

➜  text-generation-inference git:(main) ✗ pre-commit run --all-files
check yaml...............................................................Passed
fix end of files.........................................................Failed
- hook id: end-of-file-fixer
- exit code: 1
- files were modified by this hook

Fixing backends/trtllm/csrc/ffi.hpp
Fixing docs/source/multi_backend_support.md
Fixing backends/trtllm/csrc/backend.hpp
Fixing backends/trtllm/tests/test_hardware.cpp
Fixing docs/source/backends/trtllm.md
Fixing backends/trtllm/csrc/hardware.hpp
Fixing .devcontainer/Dockerfile_trtllm
Fixing backends/trtllm/tests/test_backend.cpp

trim trailing whitespace.................................................Failed
- hook id: trailing-whitespace
- exit code: 1
- files were modified by this hook

Fixing docs/source/multi_backend_support.md
Fixing docs/source/backends/trtllm.md

black....................................................................Passed
...

[HuggingFaceDocBuilderDev]

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[drbh]

merging as this PR only contains linting changes