This reverts commit 11f045bb7c.
The rpc was added together with colocated tablets in 2025.4 to support a
"shared repair" operation of a group of colocated tablets that repairs
all of them and allows also for special behavior as opposed to repairing
a single specific tablet.
It is not used anymore because we decided to not repair all colocated
tablets in a single shared operation, but to repair only the base table,
and in a later release support repairing colocated tables individually.
We can remove the rpc in 2025.4 because it is introduced in the same
version.
005807ebb8