'nullptr_t' usage.

[Daniil Mikhaylov]

Describe the bug
When trying to build POCO compiler throws an error:
Unknown type name 'nullptr_t'; did you mean 'std::nullptr_t'?

Expected behavior
POCO build is completed successfully.

Logs
Build logs:

[build] ../myproject/thirdparty/poco/Foundation/include/Poco/Any.h:563:2: error: unknown type name 'nullptr_t'; did you mean 'std::nullptr_t'?
         poco_static_assert_ptr(ValueType);
         ^
[build] ../myproject/thirdparty/poco/Foundation/include/Poco/Bugcheck.h:173:20: note: expanded from macro 'poco_static_assert_ptr'
         std::is_same_v<T, nullptr_t> || \
                           ^
[build] /usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/x86_64-linux-gnu/c++/12/bits/c++config.h:302:29: note: 'std::nullptr_t' declared here
   typedef decltype(nullptr)     nullptr_t;

Please add relevant environment information:

• Ubuntu 22.04.3 LTS | 64bit
• POCO Version: Commit 88be669

Additional context
I'm not sure about the exact commit it broke like that, because I'm using POCO as a submodule and did not update it in a while.

[Daniil Mikhaylov]

Thank you for the quick resolution on this issue!