fix: make chain-id flag not strictly required for tx commands (#10184)

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## Description

chain-id's can be specified in a client config to be used in CLI commands. This PR changes the ChainID flag to no longer be explicitly required, as this value can come from clientCtx via config.

Closes: #9644 

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CHANGELOG.md

@@ -133,6 +133,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 + [\#10061](https://github.com/cosmos/cosmos-sdk/pull/10061) Ensure that `LegacyAminoPubKey` struct correctly unmarshals from JSON
 * (server) [#10016](https://github.com/cosmos/cosmos-sdk/issues/10016) Fix marshaling of index-events into server config file.
 * (x/feegrant) [\#10049](https://github.com/cosmos/cosmos-sdk/issues/10049) Fixed the error message when `period` or `period-limit` flag is not set on a feegrant grant transaction.
+* [\#10184](https://github.com/cosmos/cosmos-sdk/pull/10184) Fixed CLI tx commands to no longer explicitly require the chain-id flag as this value can come from a user config.
 
 
 ### State Machine Breaking

client/flags/flags.go

@@ -116,8 +116,6 @@ func AddTxFlagsToCmd(cmd *cobra.Command) {
 
 	// --gas can accept integers and "auto"
 	cmd.Flags().String(FlagGas, "", fmt.Sprintf("gas limit to set per-transaction; set to %q to calculate sufficient gas automatically (default %d)", GasFlagAuto, DefaultGasLimit))
-
-	cmd.MarkFlagRequired(FlagChainID)
 }
 
 // AddPaginationFlagsToCmd adds common pagination flags to cmd