feat: Add enterprise Visual Studio subscription licensing APIs

[hariom-hp]

Summary

Adds typed EnterpriseService support for GitHub Enterprise Cloud's Visual Studio Subscriptions (VSS) licensing endpoints:

• ListVisualStudioSubscriptions: GET /enterprises/{enterprise}/visual-studio-subscriptions
• AddOrUpdateVisualStudioSubscriptionAssignment: PUT /enterprises/{enterprise}/visual-studio-subscriptions/{visual_studio_subscription_id}
• DeleteVisualStudioSubscriptionAssignment: DELETE /enterprises/{enterprise}/visual-studio-subscriptions/{visual_studio_subscription_id}

Changes

• Defined VisualStudioSubscriptions, VisualStudioSubscriptionAssignment, VisualStudioSubscriptionAssignmentRequest, and ListVisualStudioSubscriptionsOptions.
• Added the three licensing methods on EnterpriseService with OpenAPI //meta:operation directives and API documentation links.
• Added unit tests in enterprise_licenses_test.go covering success cases, request body payloads, HTTP 204 responses, bad options, and mock server failures (100% statement coverage).
• Regenerated accessors in github-accessors.go and iterators in github-iterators.go.

Validation

• script/fmt.sh
• script/generate.sh --check
• script/lint.sh (0 issues across all 12 modules)
• script/test.sh -race -covermode atomic ./... (0 failures across all 12 modules)
• go test -v -tags=integration -run=^$ ./test/integration
• git diff --check

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.52%. Comparing base (27beda9) to head (72eb6bb).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4483   +/-   ##
=======================================
  Coverage   98.51%   98.52%           
=======================================
  Files         195      195           
  Lines       17691    17735   +44     
=======================================
+ Hits        17429    17473   +44     
  Misses        262      262           

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[gmlewis]

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

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

[alexandear]

Looks like this doesn't match the schema in docs: email vs visual_studio_subscription_email, subscriptionId vs subscription_id

{
  "type": "object",
  "required": [
    "total_count",
    "visual_studio_subscriptions"
  ],
  "properties": {
    "total_count": {
      "type": "integer"
    },
    "visual_studio_subscriptions": {
      "type": "array",
      "items": {
        "title": "Visual Studio Subscription Assignment",
        "description": "Visual Studio Subscription Assignment",
        "type": "object",
        "properties": {
          "visual_studio_subscription_email": {
            "type": "string",
            "description": "The email associated with the Visual Studio subscription assignment in the visual studio portal."
          },
          "subscription_id": {
            "type": "string",
            "description": "The ID of the Visual Studio Subscription. This is a GUID that comes from the Visual Studio management portal."
          },
          "username": {
            "type": [
              "string",
              "null"
            ],
            "description": "The GitHub username of the user associated with the Visual Studio subscription assignment."
          },
          "manual_match": {
            "type": "boolean",
            "description": "Indicates if the Visual Studio subscription assignment was manually matched to a user."
          }
        }
      }
    }
  }
}

[alexandear]

Suggested change

	func (s *EnterpriseService) AddOrUpdateVisualStudioSubscriptionUserMatch(ctx context.Context, enterprise, subscriptionID string, body VisualStudioSubscriptionUserMatchRequest) (*VisualStudioSubscriptionAssignment, *Response, error) {
	func (s *EnterpriseService) AddOrUpdateVisualStudioSubscriptionAssignment(ctx context.Context, enterprise, subscriptionID string, body VisualStudioSubscriptionAssignmentRequest) (*VisualStudioSubscriptionAssignment, *Response, error) {

[alexandear]

Suggested change

	func (s *EnterpriseService) DeleteVisualStudioSubscriptionUserMatch(ctx context.Context, enterprise, subscriptionID string) (*Response, error) {
	func (s *EnterpriseService) DeleteVisualStudioSubscriptionAssignment(ctx context.Context, enterprise, subscriptionID string) (*Response, error) {

[alexandear]

Suggested change

	UserIdentifier string `json:"user_identifier"`
	UserIdentifier *string `json:"user_identifier,omitempty"`

[hariom-hp]

Thank you for the review, @alexandear

I have addressed all the feedback in the latest commit:

• Updated JSON field tags in VisualStudioSubscriptionAssignment (visual_studio_subscription_email, subscription_id) and VisualStudioSubscriptions (visual_studio_subscriptions) to align with GitHub's OpenAPI schema.
• Renamed VisualStudioSubscriptionUserMatchRequest to VisualStudioSubscriptionAssignmentRequest and updated UserIdentifier to *string with omitempty.
• Renamed the methods to AddOrUpdateVisualStudioSubscriptionAssignment and DeleteVisualStudioSubscriptionAssignment.
• Regenerated all accessors and iterators via script/generate.sh.
• Updated unit tests and verified all tests and linters pass cleanly.