fix new clang -Wdeprecated-literal-operator (no whitespace between ""…

[SvenJo]

New Clang 20 compiler warning: -Wdeprecated-literal-operator

Generate warning (and with -Werror errors) like:

/home/sven/src/json/include/tao/json/binary.hpp:94:57: error: identifier '_binary' preceded by whitespace in a literal operator declaration is deprecated [-Werror,-Wdeprecated-literal-operator]
   94 |       [[nodiscard]] std::vector< std::byte > operator"" _binary()
      |                                              ~~~~~~~~~~~^~~~~~~
      |                                              operator""_binary

[codecov]

Codecov Report

Attention: Patch coverage is 92.92035% with 8 lines in your changes missing coverage. Please review.

Project coverage is 73.98%. Comparing base (3d1d4fc) to head (f6ef3e8).

Files with missing lines	Patch %	Lines
include/tao/json/pointer.hpp	92.07%	0 Missing and 8 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #159      +/-   ##
==========================================
- Coverage   74.01%   73.98%   -0.04%     
==========================================
  Files         257      257              
  Lines        9191     9187       -4     
  Branches      804      808       +4     
==========================================
- Hits         6803     6797       -6     
  Misses       1785     1785              
- Partials      603      605       +2     

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[SvenJo]

Sorry, include format changes.