fix(lint): staticcheck S1030, QF1002 and remove unused _ctx stub

internal/tools/pr_files_diff_test.go

@@ -42,11 +42,11 @@ func buildFilesJSON(files []string, additions int) string {
 func newPRFilesDiffServer(t *testing.T, filesJSON, rawDiff string) *httptest.Server {
 	t.Helper()
 	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		switch {
-		case r.URL.Path == "/api/v1/repos/o/r/pulls/1/files":
+		switch r.URL.Path {
+		case "/api/v1/repos/o/r/pulls/1/files":
 			w.Header().Set("Content-Type", "application/json")
 			_, _ = w.Write([]byte(filesJSON))
-		case r.URL.Path == "/api/v1/repos/o/r/pulls/1.diff":
+		case "/api/v1/repos/o/r/pulls/1.diff":
 			w.Header().Set("Content-Type", "text/plain")
 			_, _ = w.Write([]byte(rawDiff))
 		default: