CLI: remove automatic jsonrpc command

Fixes CODY-2752

Previously, running `cody-agent` started the `cody-agent jsonrpc`
subcommand. This was done for historical reasons that are no longer
important. This is a breaking change and means that IDE clients will
need to explicitly mention the `api jsonrpc` subcommand now.

agent/src/index.ts

@@ -26,10 +26,6 @@ process.on('uncaughtException', e => {
 registerLocalCertificates()
 
 const args = process.argv.slice(2)
-const { operands } = rootCommand.parseOptions(args)
-if (operands.length === 0) {
-    args.push('jsonrpc')
-}
 
 rootCommand.parseAsync(args, { from: 'user' }).catch(error => {
     console.error('Error:', error)