Remove usage of transient settings to enable allocations in full restart upgrade docs (#29670)
Remove usage of transient settings to enable allocations in full restart upgrade docs (#29670)

Since we disable allocation using persistent settings, we should be consistent and remove
the setting from the persistent storage. Otherwise an accidental restart will leed for shards
not being allocated.

Relates to https://github.com/elastic/elasticsearch/pull/28757

robin13/elasticsearch,gingerwizard/elasticsearch,HonzaKral/elasticsearch,gingerwizard/elasticsearch,gfyoung/elasticsearch,coding0011/elasticsearch,robin13/elasticsearch,robin13/elasticsearch,GlenRSmith/elasticsearch,GlenRSmith/elasticsearch,nknize/elasticsearch,gingerwizard/elasticsearch,uschindler/elasticsearch,HonzaKral/elasticsearch,gfyoung/elasticsearch,scorpionvicky/elasticsearch,gfyoung/elasticsearch,gingerwizard/elasticsearch,coding0011/elasticsearch,nknize/elasticsearch,scorpionvicky/elasticsearch,uschindler/elasticsearch,robin13/elasticsearch,uschindler/elasticsearch,HonzaKral/elasticsearch,gfyoung/elasticsearch,uschindler/elasticsearch,gfyoung/elasticsearch,nknize/elasticsearch,coding0011/elasticsearch,HonzaKral/elasticsearch,nknize/elasticsearch,scorpionvicky/elasticsearch,scorpionvicky/elasticsearch,robin13/elasticsearch,gingerwizard/elasticsearch,uschindler/elasticsearch,gingerwizard/elasticsearch,nknize/elasticsearch,GlenRSmith/elasticsearch,scorpionvicky/elasticsearch,coding0011/elasticsearch,coding0011/elasticsearch,GlenRSmith/elasticsearch,gingerwizard/elasticsearch,GlenRSmith/elasticsearch