[DO NOT MERGE] Add lightning.amdgpu alias device for v0.43.0

[josephleekl]

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---

Context:
This PR introduces a new device lightning.amdgpu as an alias for lightning.kokkos

>>> qml.about()
Name: pennylane
Version: 0.43.1
...
Installed devices:
- lightning.qubit (pennylane_lightning-0.43.0)
- lightning.amdgpu (pennylane_lightning_amdgpu-0.43.0)

Users can instantiate this device with

qml.device('lightning.amdgpu')

This device also works with qjit.

Notes:

• This device is simply an alias of lightning.kokkos, there might be issues if bothlightning.amdgpu and lightning.kokkos are installed, as there may be conflicts.
• The package name is pennylane_lightning_amdgpu (e.g. pennylane_lightning_amdgpu-0.43.0-cp311-cp311-linux_x86_64.whl)
• The shared lib name is updated (lightning_amdgpu_ops.cpython-311-x86_64-linux-gnu.so), but we do not change the catalyst shared lib name (liblightning_kokkos_catalyst.so), since Catalyst will continue to think this is the lightning-kokkos device.
• To test build this, you can do:

make python

# assuming Kokkos is built in KOKKOS_INSTALL_PATH
export CMAKE_PREFIX_PATH=:"${KOKKOS_INSTALL_PATH}":/opt/rocm:$CMAKE_PREFIX_PATH
PL_BACKEND="lightning_amdgpu" \
build_options="-DCMAKE_CXX_COMPILER=hipcc -DCMAKE_CXX_FLAGS='--gcc-install-dir=/usr/lib/gcc/x86_64-linux-gnu/11/'" \
make python

# run tests
PL_DEVICE="lightning.amdgpu" python -m pytest tests/

The instructions to build a wheel actually for AMD GPU is available here.

Description of the Change:

Benefits:

Possible Drawbacks:

Related GitHub Issues:

[sc-104098]

[github-actions]

Hello. You may have forgotten to update the changelog!
Please edit .github/CHANGELOG.md with:

• A one-to-two sentence description of the change. You may include a small working example for new features.
• A link back to this PR.
• Your name (or GitHub username) in the contributors section.

[codecov]

Codecov Report

❌ Patch coverage is 2.60870% with 112 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (v0.43.0_release@63394c9). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
...ane_lightning/lightning_amdgpu/lightning_amdgpu.py	0.00%	102 Missing ⚠️
pennylane_lightning/lightning_amdgpu/__init__.py	0.00%	9 Missing ⚠️
pennylane_lightning/lightning_base/_serialize.py	50.00%	1 Missing ⚠️

Additional details and impacted files

@@                Coverage Diff                 @@
##             v0.43.0_release    #1297   +/-   ##
==================================================
  Coverage                   ?   91.34%           
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  Files                      ?      184           
  Lines                      ?    27672           
  Branches                   ?        0           
==================================================
  Hits                       ?    25276           
  Misses                     ?     2396           
  Partials                   ?        0           

Flag	Coverage Δ
unit_tests	91.34% <2.60%> (?)

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[maliasadi]

Nice work @josephleekl! Happy to have another look after updating the docs

[josephleekl]

new Docker build test https://github.com/PennyLaneAI/pennylane-lightning/actions/runs/19772868012/job/56660304392