fix: add server_url attribute to github context (#1727)

* fix: add `server_url` attribute to github context

The `server_urL` attribute was missing in the `github` context.
Previously it was exposed as environment variable only.

Closes #1726

* fix: also set `api_url` and `graphql_url` attributes

pkg/model/github_context.go

@@ -36,6 +36,9 @@ type GithubContext struct {
 	RetentionDays    string                 `json:"retention_days"`
 	RunnerPerflog    string                 `json:"runner_perflog"`
 	RunnerTrackingID string                 `json:"runner_tracking_id"`
+	ServerURL        string                 `json:"server_url "`
+	APIURL           string                 `json:"api_url"`
+	GraphQLURL       string                 `json:"graphql_url"`
 }
 
 func asString(v interface{}) string {