Update test mock to match corrected inline fragments

Author: iulia-b

pkg/github/granular_tools_test.go

@@ -810,9 +810,18 @@ func TestGranularSetIssueFields(t *testing.T) {
 							URL    githubv4.String
 						}
 						IssueFieldValues []struct {
-							Field struct {
+							TextValue struct {
+								Value string
+							} `graphql:"... on IssueFieldTextValue"`
+							SingleSelectValue struct {
 								Name string
+							} `graphql:"... on IssueFieldSingleSelectValue"`
+							DateValue struct {
+								Value string
 							} `graphql:"... on IssueFieldDateValue"`
+							NumberValue struct {
+								Value float64
+							} `graphql:"... on IssueFieldNumberValue"`
 						}
 					} `graphql:"setIssueFieldValue(input: $input)"`
 				}{},