Description of problem:

Older clients can crash the monitor when pg_upmap_primaries is non empty. pg_upmap_primaries can only be generated using the offline tool in Reef.

ceph crash info
2023-07-10T19:02:42.116150Z_8061077a-2257-49c7-8088-c94a5a580f6a
{
     "assert_condition": "pg_upmap_primaries.empty()",
     "assert_file": "/home/jenkins-build/build/workspace/ceph-build/ARCH/x86_64/AVAILABLE_ARCH/x86_64/AVAILABLE_DIST/centos8/DIST/centos8/MACHINE_SIZE/gigantic/release/18.1.2/rpm/el8/BUILD/ceph-18.1.2/src/osd/OSDMap.cc",
     "assert_func": "void OSDMap::encode(ceph::buffer::v15_2_0::list&, uint64_t) const",
     "assert_line": 3239,
     "assert_msg": "/home/jenkins-build/build/workspace/ceph-build/ARCH/x86_64/AVAILABLE_ARCH/x86_64/AVAILABLE_DIST/centos8/DIST/centos8/MACHINE_SIZE/gigantic/release/18.1.2/rpm/el8/BUILD/ceph-18.1.2/src/osd/OSDMap.cc: In function 'void OSDMap::encode(ceph::buffer::v15_2_0::list&, uint64_t) const' thread 7f95f67cb700 time 2023-07-10T19:02:42.106910+0000\n/home/jenkins-build/build/workspace/ceph-build/ARCH/x86_64/AVAILABLE_ARCH/x86_64/AVAILABLE_DIST/centos8/DIST/centos8/MACHINE_SIZE/gigantic/release/18.1.2/rpm/el8/BUILD/ceph-18.1.2/src/osd/OSDMap.cc: 3239: FAILED ceph_assert(pg_upmap_primaries.empty())\n",
     "assert_thread_name": "ms_dispatch",
     "backtrace": [
         "/lib64/libpthread.so.0(+0x12cf0) [0x7f9601c12cf0]",
         "gsignal()",
         "abort()",
         "(ceph::__ceph_assert_fail(char const*, char const*, int, char const*)+0x18f) [0x7f96043f0e15]",
         "/usr/lib64/ceph/libceph-common.so.2(+0x2a9f81) [0x7f96043f0f81]",
         "(OSDMap::encode(ceph::buffer::v15_2_0::list&, unsigned long) const+0x1229) [0x7f96048a4a19]",
         "(OSDMonitor::reencode_full_map(ceph::buffer::v15_2_0::list&, unsigned long)+0xe0) [0x55d71adf3d30]",
         "(OSDMonitor::get_version_full(unsigned long, unsigned long, ceph::buffer::v15_2_0::list&)+0x326) [0x55d71ae27616]",
         "(OSDMonitor::build_latest_full(unsigned long)+0x306) [0x55d71ae27986]",
         "(OSDMonitor::check_osdmap_sub(Subscription*)+0x7a) [0x55d71ae2b81a]",
         "(Monitor::handle_subscribe(boost::intrusive_ptr<MonOpRequest>)+0xeed) [0x55d71ac4b25d]",
         "(Monitor::dispatch_op(boost::intrusive_ptr<MonOpRequest>)+0x7d6) [0x55d71ac5fea6]",
         "(Monitor::_ms_dispatch(Message*)+0x406) [0x55d71ac610a6]",
         "(Dispatcher::ms_dispatch2(boost::intrusive_ptr<Message> const&)+0x5d) [0x55d71ac91bcd]",
         "(Messenger::ms_deliver_dispatch(boost::intrusive_ptr<Message> const&)+0x478) [0x7f9604669c08]",
         "(DispatchQueue::entry()+0x50f) [0x7f9604666daf]",
         "(DispatchQueue::DispatchThread::entry()+0x11) [0x7f960472d391]",
         "/lib64/libpthread.so.0(+0x81ca) [0x7f9601c081ca]",
         "clone()" 
     ],
     "ceph_version": "18.1.2",
     "crash_id": "2023-07-10T19:02:42.116150Z_8061077a-2257-49c7-8088-c94a5a580f6a",
     "entity_name": "mon.reef03",
     "os_id": "centos",
     "os_name": "CentOS Stream",
     "os_version": "8",
     "os_version_id": "8",
     "process_name": "ceph-mon",
     "stack_sig": "36e64bb49053b7de85c9cf46c6739fe42dd443b8320310aef2318e06c48ee87e",
     "timestamp": "2023-07-10T19:02:42.116150Z",
     "utsname_hostname": "reef03",
     "utsname_machine": "x86_64",
     "utsname_release": "5.4.0-147-generic",
     "utsname_sysname": "Linux",
     "utsname_version": "#164-Ubuntu SMP Tue Mar 21 14:23:17 UTC 2023" 
}