Update size.hpp

[blozano-tt]

Problem description

Fix spurrious compiler error seen by @afuller-TT

/home/ubuntu/actions-runner/_work/tt-metal/tt-metal/ttnn/cpp/ttnn/tensor/layout/size.hpp:30:50: error: 'forward_as_tuple' is not a member of 'std'
   30 |     static constexpr auto attribute_names = std::forward_as_tuple("height", "width");

/home/ubuntu/actions-runner-2/_work/tt-metal/tt-metal/ttnn/cpp/ttnn/tensor/layout/size.hpp:14:26: error: 'size_t' was not declared in this scope; did you mean 'std::size_t'?
   14 |     Size(const std::pair<size_t, size_t>& size);
      |                          ^~~~~~
      |                          std::size_t
In file included from /usr/include/c++/12/type_traits:38,
                 from /usr/include/c++/12/concepts:44,
                 from /usr/include/c++/12/compare:39,
                 from /usr/include/c++/12/array:38,
                 from /home/ubuntu/actions-runner-2/_work/tt-metal/tt-metal/ttnn/cpp/ttnn/tensor/layout/size.hpp:7:
/usr/include/x86_64-linux-gnu/c++/12/bits/c++config.h:298:33: note: 'std::size_t' declared here
  298 |   typedef __SIZE_TYPE__         size_t;

What's changed

Include what you use, fully qualify std::

Checklist

• Post commit CI passes
• Blackhole Post commit (if applicable)
• Model regression CI testing passes (if applicable)
• Device performance regression CI testing passes (if applicable)
• New/Existing tests provide coverage for changes