FTBFS with GCC 12

squid's "upstream-test-suite" dep8 test is currently FTBFSing with GCC 12 on Kinetic:

libtool: compile: g++ -DHAVE_CONFIG_H -DDEFAULT_CONFIG_FILE=\"/etc/squid.conf\" -DDEFAULT_SQUID_DATA_DIR=\"/usr/share\" -DDEFAULT_SQUID_CONFIG_DIR=\"/etc\" -I../.. -I../../include -I../../lib -I../../src -I../../include -isystem /usr/include/mit-krb5 -Wdate-time -D_FORTIFY_SOURCE=2 -I/usr/include/libxml2 -Wall -Wpointer-arith -Wwrite-strings -Wcomments -Wshadow -Woverloaded-virtual -Werror -pipe -D_REENTRANT -I/usr/include/libxml2 -I/usr/include/p11-kit-1 -g -O2 -ffile-prefix-map=/tmp/autopkgtest.6E1e0D/build.pFL/src=. -flto=auto -ffat-lto-objects -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -march=native -c File.cc -fPIC -DPIC -o .libs/File.o
In file included from ../../src/base/File.h:12,
                 from File.cc:10:
../../src/sbuf/SBuf.h:48:34: error: 'template<class _Category, class _Tp, class _Distance, class _Pointer, class _Reference> struct std::iterator' is deprecated [-Werror=deprecated-declarations]
   48 | class SBufIterator : public std::iterator<std::input_iterator_tag, char>
      | ^~~~~~~~
In file included from /usr/include/c++/12/string:45,
                 from /usr/include/c++/12/stdexcept:39,
                 from ../../src/base/TextException.h:14,
                 from ../../src/sbuf/SBuf.h:15:
/usr/include/c++/12/bits/stl_iterator_base_types.h:127:34: note: declared here
  127 | struct _GLIBCXX17_DEPRECATED iterator
      | ^~~~~~~~
cc1plus: all warnings being treated as errors