Rust: Remove more redundant models.

Author: geoffw0

rust/ql/lib/codeql/rust/frameworks/stdlib/net.model.yml

@@ -10,7 +10,3 @@ extensions:
       extensible: summaryModel
     data:
       - ["<std::net::tcp::TcpStream>::try_clone", "Argument[self]", "ReturnValue.Field[core::result::Result::Ok(0)]", "taint", "manual"]
-      - ["<_ as std::io::Read>::read", "Argument[self]", "Argument[0].Reference", "taint", "manual"]
-      - ["<_ as std::io::Read>::read_to_string", "Argument[self]", "Argument[0].Reference", "taint", "manual"]
-      - ["<_ as std::io::Read>::read_to_end", "Argument[self]", "Argument[0].Reference", "taint", "manual"]
-      - ["<_ as std::io::Read>::read_exact", "Argument[self]", "Argument[0].Reference", "taint", "manual"]