Describe the bug
There are A, B, C, D and E 5 BEs.
tablet t has 4 replicas in A(good), B(good), C(version miss) and D(good).

If now mark D and E as decommissioned. FE will never delete replica in C and can not choose D or E to create new replica.

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The complex situation is:
There are A, B, C, D and E 5 BEs.
tabletA has replicas a1(A)(good), a2(B)(good), a3(C)(version miss), a4(D)(good)
tabletB has replicas b1(A)(good), b2(B)(good), b3(c)(version miss), b4(E)(good)
Because tabletA and tabletB are all REPLICA_RELOCATING, but they can not find a BE to create new replica.
a4 prevents D from being deleted and b4 prevents E from being deleted.
The repair and decommission will hang.