Update link in Cargo.toml (#4006)

https://docs.rs/linera-indexer-graphql-client/latest/linera_indexer_graphql_client/
- dead

---------

Signed-off-by: strmfos <[email protected]>

Author: strmfos

linera-indexer/graphql-client/Cargo.toml

@@ -2,7 +2,6 @@
 name = "linera-indexer-graphql-client"
 description = "GraphQL client for the indexer"
 readme = "README.md"
-documentation = "https://docs.rs/linera-indexer-graphql-client/latest/linera_indexer_graphql_client/"
 
 authors.workspace = true
 edition.workspace = true