Intel 23 doesn't like the deprecated test

[VictorEijkhout]

[  0%] Building CXX object test/CMakeFiles/range.v3.constexpr_core.dir/constexpr_core.cpp.o
cd /work2/00434/eijkhout/rangev3/build-0.12.0-clx-intel23/test && /opt/intel/oneapi/compiler/2023.1.0/linux/bin/icpx  -I/work2/00434/eijkhout/rangev3/rangev3-0.12.0/include -O3 -DNDEBUG -std=c++14 -Wall -Wextra -Werror -fdiagnostics-show-template-tree -ftemplate-backtrace-limit=0 -fmacro-backtrace-limit=1 -fomit-frame-pointer -Ofast -fstrict-aliasing -fstrict-vtable-pointers -ffast-math -fvectorize -fsized-deallocation -march=native -mtune=native -DRANGES_CXX_ALIGNED_NEW=0 -Weverything -pedantic -pedantic-errors -Wno-c++98-compat -Wno-c++98-compat-pedantic -Wno-weak-vtables -Wno-padded -Wno-missing-variable-declarations -Wno-documentation -Wno-documentation-unknown-command -Wno-old-style-cast -MD -MT test/CMakeFiles/range.v3.constexpr_core.dir/constexpr_core.cpp.o -MF CMakeFiles/range.v3.constexpr_core.dir/constexpr_core.cpp.o.d -o CMakeFiles/range.v3.constexpr_core.dir/constexpr_core.cpp.o -c /work2/00434/eijkhout/rangev3/rangev3-0.12.0/test/constexpr_core.cpp
/work2/00434/eijkhout/rangev3/rangev3-0.12.0/test/config.cpp:14:66: error: no previous prototype for function 'foo' [-Werror,-Wmissing-prototypes]
RANGES_DEPRECATED("compile test for \"RANGES_DEPRECATED\"") void foo() {}
                                                                 ^
/work2/00434/eijkhout/rangev3/rangev3-0.12.0/test/config.cpp:14:61: note: declare 'static' if the function is not intended to be used outside of this translation unit
RANGES_DEPRECATED("compile test for \"RANGES_DEPRECATED\"") void foo() {}
                                                            ^
                                                            static
1 error generated.