Editing gen_jit_shape_functions to make lintrunner happy (#79571)

Somehow even with clang-format off, it was unhappy with this line

>>> Lint for torch/csrc/jit/runtime/serialized_shape_function_registry.cpp:

  Warning (CLANGFORMAT) format
    See https://clang.llvm.org/docs/ClangFormat.html.
    Run `lintrunner -a` to apply this patch.

    You can run `lintrunner -a` to apply this patch.

    2855  2855 |   return shape_mappings;
    2856  2856 | }
    2857  2857 |
    2857       |-
    2859  2858 | // clang-format on
    2860  2859 |
    2861  2860 | } // namespace jit

Note that there is no changes to `serialized_shape_function_registry.cpp` in this diff because I had to manually run `lintrunner` to make it format the code correctly in the previous diff so that we can land it.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/79571
Approved by: https://github.com/eellison

torchgen/shape_functions/gen_jit_shape_functions.py

@@ -41,7 +41,6 @@ const std::string& GetSerializedShapeFunctions() {
 """
 
 DECOMP_END = r"""
-
 // clang-format on
 
 } // namespace jit