[Fix] Remove invalid graphs

[Sigri44]

Hello, since recent RealT communication, need to remove definitely deprecated graphs :

RMM-RealT-v2 :
https://github.com/RealToken-Community/dashboard-v2/blame/8a27ca2fcc895382e90fa84e476cdd71e4116aae/src/repositories/subgraphs/clients.ts#L32
OLD : https://thegraph.com/explorer/subgraphs/CxvZgcPjmtvFeSoSW9N563K7ZcHCwLVv8kXMbmuBKhv1
NEW : https://thegraph.com/explorer/subgraphs/GLPJ8va2UbjoTpcQQwG8FXQYYQChYZWczuDubsQfzR7K

YAM-History :
https://github.com/RealToken-Community/dashboard-v2/blame/8a27ca2fcc895382e90fa84e476cdd71e4116aae/src/repositories/subgraphs/clients.ts#L64
OLD : https://thegraph.com/explorer/subgraphs/4eJa4rKCR5f8fq48BKbYBPvf7DWHppGZRvfiVUSFXBGR
NEW : https://thegraph.com/explorer/subgraphs/2RHaLwFYozfHN2bbwUmAoQeJuGn7FX5UREGCkZFwfiZi
(Need to make a PR into RealT graph, to include new field in their graphs if needed)

Thx !