Support FP8 in op flip, index_put, and index.Tensor

[chunhuanMeng]

To solve #2207
Extends support for float8 data types across various XPU tensor indexing and transformation kernels, ensuring these operations are compatible with the new types. It also adds a regression test for flipping float8 tensors and removes the skip for float8 indexing tests.

Float8 type support:

• Updated dispatch macros in XPUScalar.cpp and Indexing.cpp to include AT_FLOAT8_TYPES, enabling float8 support in scalar extraction, indexing, index_put, and deterministic index_put kernels.
• Modified flip_kernel in TensorTransformationsKernels.cpp to support float8 and barebones unsigned types, updating the dispatch mechanism accordingly.
• Included the new dispatch header Dispatch_v2.h for the updated dispatch macros.

Testing improvements:

• Added a regression test for flipping float8 tensors in test_index_and_index_put.py to verify correctness of the operation on XPU.
• Removed the skip for float8 tests in test_indexing_xpu.py, re-enabling these tests now that support is implemented.

[Copilot]

Pull Request Overview

This PR adds FP8 support to XPU tensor operations including flip, index, and index_put operations by migrating from legacy dispatch macros to the newer AT_DISPATCH_V2 system.

• Migrates flip_kernel from AT_DISPATCH_ALL_TYPES_AND_COMPLEX_AND3 to AT_DISPATCH_V2
• Migrates index_kernel and index_put_kernel from AT_DISPATCH_ALL_TYPES_AND_COMPLEX_AND4 to AT_DISPATCH_V2
• Adds FP8 type support through AT_FLOAT8_TYPES expansion

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/ATen/native/xpu/sycl/TensorTransformationsKernels.cpp	Updates flip_kernel to use AT_DISPATCH_V2 with FP8 support
src/ATen/native/xpu/sycl/Indexing.cpp	Updates index_kernel and index_put_kernel to use AT_DISPATCH_V2 with FP8 support

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[chunhuanMeng]