fix: quantity being a float and not an int

The API doc is not consistent with the actual output from the api.
The quantity is not an int, but a float.

Author: DocEmmetBrown

github/billing.go

@@ -87,7 +87,7 @@ type UsageItem struct {
 	Date           *string  `json:"date"`
 	Product        *string  `json:"product"`
 	SKU            *string  `json:"sku"`
-	Quantity       *int     `json:"quantity"`
+	Quantity       *float64 `json:"quantity"`
 	UnitType       *string  `json:"unitType"`
 	PricePerUnit   *float64 `json:"pricePerUnit"`
 	GrossAmount    *float64 `json:"grossAmount"`

github/billing_test.go

@@ -556,7 +556,7 @@ func TestBillingService_GetUsageReportOrg(t *testing.T) {
 				Date:             Ptr("2023-08-01"),
 				Product:          Ptr("Actions"),
 				SKU:              Ptr("Actions Linux"),
-				Quantity:         Ptr(100),
+				Quantity:         Ptr(100.0),
 				UnitType:         Ptr("minutes"),
 				PricePerUnit:     Ptr(0.008),
 				GrossAmount:      Ptr(0.8),
@@ -637,7 +637,7 @@ func TestBillingService_GetUsageReportUser(t *testing.T) {
 				Date:           Ptr("2023-08-15"),
 				Product:        Ptr("Codespaces"),
 				SKU:            Ptr("Codespaces Linux"),
-				Quantity:       Ptr(50),
+				Quantity:       Ptr(50.0),
 				UnitType:       Ptr("hours"),
 				PricePerUnit:   Ptr(0.18),
 				GrossAmount:    Ptr(9.0),