fix(cli): add support for 0.79

[tido64]

Description

indexPageMiddleware is no longer needed/used in 0.79

Test plan

In RNTA:

yarn set-react-version 0.79
yarn
cd example
yarn start

This should not crash:

/~/node_modules/connect/index.js:87
  if (typeof handle.handle === 'function') {
                    ^

TypeError: Cannot read properties of undefined (reading 'handle')
    at Function.use (/~/node_modules/connect/index.js:87:21)
    at exports.runServer (/~/node_modules/metro/src/index.flow.js:148:15)
    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)
    at async rnxStart (/~/node_modules/@rnx-kit/cli/lib/start.js:152:28)