[BUG] emulsify-cli assumes that a custom starter theme's default branch is 'master'

[calebtr-metro]

Describe the bug
emulsify-cli assumes that a custom starter theme's default branch is 'master'.

The error is:

fatal: Remote branch master not found in upstream origin

However if you specify a --checkout, then starter theme is installed correctly.

To Reproduce
Steps to reproduce the behavior:

1. Initialize a project with a custom starter theme repository where the default branch is not "master"; verify that it is valid by specifying a checkout on the command line:

   emulsify init -p drupal --starter git@github.com:calebtr-metro/emulsify-starter-demonstration.git --checkout main . test-success

2. Initialize a project with the same repository but leave out the --checkout flag:

   emulsify init -p drupal --starter git@github.com:calebtr-metro/emulsify-starter-demonstration.git . test-fail

3. See error.

fatal: Remote branch master not found in upstream origin

Expected behavior
emulsify-cli should identify a repository's correct default branch / HEAD.

Additional context

• node v20.11.1
• emulsify v1.9.0