chore(gatsby-cli): Convert init-starter to typescript

[mottox2]

Description

Convert init-starter to typescript

Related Issues

Related to #21995

[blainekasten]

This looks great! Thank you so much!

[blainekasten]

@mottox2 lint is failing:

/home/circleci/project/packages/gatsby-cli/src/init-starter.ts
   17:39  warning  Unexpected any. Specify a different type        @typescript-eslint/no-explicit-any
   19:10  error    'spawnWithArgs' was used before it was defined  @typescript-eslint/no-use-before-define
   21:23  error    Missing return type on function                 @typescript-eslint/explicit-function-return-type
   21:64  warning  Unexpected any. Specify a different type        @typescript-eslint/no-explicit-any
  161:32  warning  Unexpected any. Specify a different type        @typescript-eslint/no-explicit-any
  192:18  error    Missing return type on function                 @typescript-eslint/explicit-function-return-type
  239:6   error    Use an `interface` instead of a `type`          @typescript-eslint/consistent-type-definitions
  243:24  error    Missing return type on function                 @typescript-eslint/explicit-function-return-type```

[mottox2]

Sorry, I fixed it. Thank you for reviewing.

[blainekasten]

is it possible to type this? seems like it should be available maybe on execa or something?

[blainekasten]

I'm going to merge because this is the only concern i see, but would love to see this get fixed in a follow up!