Fix crash running yarn flags --sort flag

[eps1lon]

Summary

Fixes

$ yarn flags                        
yarn run v1.22.10
$ node ./scripts/flags/flags.js
/Users/sebastian.silbermann/react/scripts/flags/flags.js:323
      rowB[sortChannel].toString().localeCompare(rowA[sortChannel])
                        ^

TypeError: Cannot read properties of undefined (reading 'toString')
    at /Users/sebastian.silbermann/react/scripts/flags/flags.js:323:25
    at Array.sort (<anonymous>)
    at Object.<anonymous> (/Users/sebastian.silbermann/react/scripts/flags/flags.js:322:27)
    at Module._compile (node:internal/modules/cjs/loader:1356:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1414:10)
    at Module.load (node:internal/modules/cjs/loader:1197:32)
    at Function.Module._load (node:internal/modules/cjs/loader:1013:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:128:12)
    at node:internal/main/run_main_module:28:49

Node.js v18.19.1
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

How did you test this change?

• yarn flags
• yarn flags --sort flags

[react-sizebot]

Comparing: 2e470a7...acaae63

Critical size changes

Includes critical production bundles, as well as any change greater than 2%:

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
oss-stable/react-dom/cjs/react-dom.production.min.js	=	176.83 kB	176.83 kB	=	55.11 kB	55.11 kB
oss-experimental/react-dom/cjs/react-dom.production.min.js	=	178.83 kB	178.83 kB	=	55.69 kB	55.69 kB
facebook-www/ReactDOM-prod.classic.js	=	592.18 kB	592.18 kB	=	104.43 kB	104.43 kB
facebook-www/ReactDOM-prod.modern.js	=	575.46 kB	575.46 kB	=	101.43 kB	101.43 kB
test_utils/ReactAllWarnings.js	Deleted	66.26 kB	0.00 kB	Deleted	16.32 kB	0.00 kB

Significant size changes

Includes any change greater than 0.2%:

Expand to show

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
test_utils/ReactAllWarnings.js	Deleted	66.26 kB	0.00 kB	Deleted	16.32 kB	0.00 kB

Generated by 🚫 dangerJS against acaae63

[jackpope]

Thanks for fixing. Was just hitting this myself