Bump syn to 2.0

[DCNick3]

Recently syn has had a new major release, and proc macro ecosystem has largely migrated too.

It might be a good idea to update

Update progress:

• iroha_data_model_derive (Rewrite iroha_data_model_derive to use syn 2.0 #3882, [refactor] #3822, #3737, #2437: Refactor iroha_data_model_derive #3897)
• iroha_ffi_derive (Rewrite iroha_ffi_derive to use syn 2.0 #3814, [refactor] #3814: Update iroha_ffi_derive to use syn 2.0  #3830)
• iroha_schema_derive ([refactor]: update iroha_schema_derive to use syn 2.0 #3759)
• iroha_primitives_derive ([refactor]: introduce syn 2.0, manyhow and darling for proc-macros #3727)
• iroha_version_derive ([refactor]: introduce syn 2.0, manyhow and darling for proc-macros #3727)
• iroha_derive ([refactor]: introduce syn 2.0, manyhow and darling for proc-macros #3727)
• iroha_telemetry_derive (Migrate iroha_telemetry_derive to syn 2.0 #3909, [refactor]: update iroha_telemetry_derive to use syn2 #4168)
• iroha_futures_derive (Migrate iroha_futures_derive to syn 2.0 #3911, [refactor] #3911: Migrate iroha_futures_derive to syn 2.0 #3915)
• iroha_torii_derive (Rewrite torii_derive to use syn 2.0 #4117, [refactor]: update iroha_torii_macro to use syn 2.0 #4118)
• iroha_config_base_derive will be removed as part of Minimal major configuration overhaul #4161
• iroha_executor_derive (Migrate iroha_smart_contract_derive, iroha_executor_derive and iroha_trigger_derive to syn 2.0 #3934, [refactor] #3934: Migrate iroha_smart_contract_derive, iroha_executor_derive and iroha_trigger_derive to syn 2.0 #3935)
• iroha_core_wasm_codec_derive (Migrate iroha_core_wasm_codec_derive to syn 2.0 #3943)