build failure with libc++ 21

[pobrn]

When building with clang + libc++ 21, the following is encountered:

[3/4] Compiling C++ object src/libpisp.so.1.3.0.p/helpers_media_device.cpp.o
FAILED: [code=1] src/libpisp.so.1.3.0.p/helpers_media_device.cpp.o 
/usr/bin/ccache clang++ -Isrc/libpisp.so.1.3.0.p -Isrc -I../src -Isrc/libpisp -I../src/libpisp -I../subprojects/nlohmann_json-3.12.0/single_include -fdiagnostics-color=always -D_LIBCPP_HARDENING_MODE=_LIBCPP_HARDENING_MODE_FAST -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wextra -Werror -std=c++17 -O3 -DPISP_LOGGING_ENABLE=0 -Wno-address-of-packed-member -stdlib=libc++ -fPIC -pthread -MD -MQ src/libpisp.so.1.3.0.p/helpers_media_device.cpp.o -MF src/libpisp.so.1.3.0.p/helpers_media_device.cpp.o.d -o src/libpisp.so.1.3.0.p/helpers_media_device.cpp.o -c ../src/helpers/media_device.cpp
../src/helpers/media_device.cpp:218:20: error: implicit instantiation of undefined template 'std::basic_stringstream<char>'
  218 |         std::stringstream ss;
      |                           ^
/usr/bin/../include/c++/v1/__fwd/sstream.h:30:7: note: template is declared here
   30 | class basic_stringstream;
      |       ^
1 error generated.
ninja: build stopped: subcommand failed.

media_device.cpp should probably include <sstream> and not <ostream>.

[naushir]

Fixed with #60.