These settings were deprecated in 7.13+ in #72835 and are now removed by this commit.
This commit also ensures that the settings are removed from index metadata when the metadata is
loaded. The reason for this is that if we allow the settings to remain (because they are not
technically "invalid"), then the index will not be able to be allocated, because the
FilterAllocationDecider will be looking for nodes with the _tier attribute.
95bccda599