fix!: Enterprise App installation repos options structs

[zry98]

BREAKING CHANGE: SelectedRepositoryIDs []int64 is now Repositories []string in *AppInstallationRepositoriesOptions.

The PR #3831 added bindings for the enterprise org-installation repository endpoints, but the request body struct uses a wrong field selected_repository_ids ([]int64), while the actual API expects repositories ([]string) according to GitHub REST API documentation: https://docs.github.com/en/enterprise-cloud@latest/rest/enterprise-admin/organization-installations?apiVersion=2022-11-28

Breaking change

Callers using SelectedRepositoryIDs []int64 must change to Repositories []string and switch the values from ID integers to name strings.

The structs AppInstallationRepositoriesOptions and UpdateAppInstallationRepositoriesOptions are also renamed to AppInstallationRepositoriesRequest and UpdateAppInstallationRepositoriesRequest respectively (the Options suffix is reserved for query parameters in this repo; these are request bodies and should use Request #4298 (comment)).

// before
opts1 := AppInstallationRepositoriesOptions{
  SelectedRepositoryIDs: []int64{12345, 67890},
}
opts2 := UpdateAppInstallationRepositoriesRequest{
  RepositorySelection:   Ptr("selected"),
  SelectedRepositoryIDs: []int64{12345, 67890},
}

// after
opts1 := AppInstallationRepositoriesRequest{
  Repositories: []string{"repo-a", "repo-b"},
}
opts2 := UpdateAppInstallationRepositoriesRequest{
  RepositorySelection: Ptr("selected"),
  Repositories:        []string{"repo-a", "repo-b"},
}

Although it wasn't working correctly before.

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.47%. Comparing base (952dff0) to head (bf9cf6a).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4298   +/-   ##
=======================================
  Coverage   97.46%   97.47%           
=======================================
  Files         192      193    +1     
  Lines       19258    19310   +52     
=======================================
+ Hits        18770    18822   +52     
  Misses        270      270           
  Partials      218      218           

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[gmlewis]

Thank you, @zry98!
LGTM.
Awaiting second LGTM+Approval from any other contributor to this repo before merging.

cc: @stevehipwell - @alexandear - @zyfy29 - @Not-Dhananjay-Mishra

[pdewilde]

These really belong in https://github.com/google/go-github/blob/master/github/enterprise_app_installation.go along with the other APIs defined in https://docs.github.com/enterprise-cloud@latest/rest/enterprise-admin/organization-installations