This bug was initially created as a copy of Bug #2242987

I am copying this bug because: 



Description of problem:
RGW daemon crashes on with "ceph_assert(index.type == BucketIndexType::Normal)" when placement target is indexless.

Version-Release number of selected component (if applicable):
18.2.0-79.el9cp

How reproducible:
always

Steps to Reproduce:
1. Deploy a cluster on 7.0(18.2.0-79.el9cp)
2. Followed the object gateway guide [1] to change the placement to indexless 
2a) add new placement to zonegroup:
  radosgw-admin zonegroup placement add --rgw-zonegroup="default" \
  --placement-id="indexless-placement"
2b) Add new placement to zone
 radosgw-admin zone placement add --rgw-zone="default" \
   --placement-id="indexless-placement" \
   --data-pool="default.rgw.buckets.data" \
   --index-pool="default.rgw.buckets.index" \
   --data_extra_pool="default.rgw.buckets.non-ec" \
   --placement-index-type="indexless"
2c) set zonegroup’s default placement to indexless-placement
  radosgw-admin zonegroup placement default --placement-id "indexless-placement"
3. Perform restart of daemon for changes to take effect.
4. RGW daemon silently crashes with "ceph_assert(index.type == BucketIndexType::Normal)"

[1]: https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/6/html-single/object_gateway_guide/index#creating-indexless-buckets_rgw

Actual results:
rgw daemon silently crashes upon restart with indexless placement target

Expected results:
No crash seen 

Additional info:
Snippet of Crash:
    -4> 2023-10-10T03:10:57.211+0000 7f4089572640 -1 /builddir/build/BUILD/ceph-18.2.0/src/rgw/rgw_bucket_layout.h: In function 'uint32_t rgw::num_shards(const rgw::bucket_index_layout&)' thread 7f4089572640 time 2023-10-10T03:10:57.210080+0000
/builddir/build/BUILD/ceph-18.2.0/src/rgw/rgw_bucket_layout.h: 269: FAILED ceph_assert(index.type == BucketIndexType::Normal)

 ceph version 18.2.0-79.el9cp (56bbf1a74fb28dfc94f31cedcb46d9f55b1eda56) reef (stable)
 1: (ceph::__ceph_assert_fail(char const*, char const*, int, char const*)+0x12e) [0x7f40b440ff57]
 2: /usr/lib64/ceph/libceph-common.so.2(+0x161115) [0x7f40b4410115]
 3: (RGWRados::check_bucket_shards(RGWBucketInfo const&, rgw_bucket const&, unsigned long, DoutPrefixProvider const*)+0x417) [0x55a0690ab197]
 4: (rgw_user_sync_all_stats(DoutPrefixProvider const*, rgw::sal::Driver*, rgw::sal::User*, optional_yield)+0x1bd) [0x55a068fc60bd]
 5: (RGWUserStatsCache::sync_user(DoutPrefixProvider const*, rgw_user const&, optional_yield)+0x209) [0x55a068ef4b09]
 6: (RGWUserStatsCache::sync_all_users(DoutPrefixProvider const*, optional_yield)+0x367) [0x55a068ef51f7]
 7: /usr/bin/radosgw(+0x5ae884) [0x55a068ef5884]
 8: /lib64/libc.so.6(+0x9f802) [0x7f40b31a5802]
 9: /lib64/libc.so.6(+0x3f450) [0x7f40b3145450]

    -3> 2023-10-10T03:10:57.211+0000 7f408a574640  5 lifecycle: RGWLC::process(): ENTER: index: 15 worker ix: 2
    -2> 2023-10-10T03:10:57.214+0000 7f408c578640  5 lifecycle: RGWLC::process() process shard rollover lc_shard=lc.28 head.marker= head.shard_rollover_date=0
    -1> 2023-10-10T03:10:57.214+0000 7f4092d85640 20 garbage collection: RGWGC::process cls_rgw_gc_list returned with returned:0, entries.size=0, truncated=0, next_marker=''
     0> 2023-10-10T03:10:57.214+0000 7f4089572640 -1 *** Caught signal (Aborted) **
 in thread 7f4089572640 thread_name:rgw_user_st_syn

 ceph version 18.2.0-79.el9cp (56bbf1a74fb28dfc94f31cedcb46d9f55b1eda56) reef (stable)
 1: /lib64/libc.so.6(+0x54df0) [0x7f40b315adf0]
 2: /lib64/libc.so.6(+0xa154c) [0x7f40b31a754c]
 3: raise()
 4: abort()
 5: (ceph::__ceph_assert_fail(char const*, char const*, int, char const*)+0x188) [0x7f40b440ffb1]
 6: /usr/lib64/ceph/libceph-common.so.2(+0x161115) [0x7f40b4410115]
 7: (RGWRados::check_bucket_shards(RGWBucketInfo const&, rgw_bucket const&, unsigned long, DoutPrefixProvider const*)+0x417) [0x55a0690ab197]
 8: (rgw_user_sync_all_stats(DoutPrefixProvider const*, rgw::sal::Driver*, rgw::sal::User*, optional_yield)+0x1bd) [0x55a068fc60bd]
 9: (RGWUserStatsCache::sync_user(DoutPrefixProvider const*, rgw_user const&, optional_yield)+0x209) [0x55a068ef4b09]
 10: (RGWUserStatsCache::sync_all_users(DoutPrefixProvider const*, optional_yield)+0x367) [0x55a068ef51f7]
 11: /usr/bin/radosgw(+0x5ae884) [0x55a068ef5884]
 12: /lib64/libc.so.6(+0x9f802) [0x7f40b31a5802]
 13: /lib64/libc.so.6(+0x3f450) [0x7f40b3145450]
 NOTE: a copy of the executable, or `objdump -rdS <executable>` is needed to interpret this.

PFA, the coredump, rgw logs at http://magna002.ceph.redhat.com/ceph-qe-logs/madhavi/indexless/