[AutoDiff] Disable failing test: SR-13250. (#32981)

Author: dan-zheng

test/AutoDiff/validation-test/differentiable_protocol_requirements.swift

@@ -1,6 +1,12 @@
 // RUN: %target-run-simple-swift
 // REQUIRES: executable_test
 
+// Disabled due to test failure with `-O`: SR-13250.
+// SR-13250 is tracking the fix for compiling this test with optimizations.
+// XFAIL: swift_test_mode_optimize
+// XFAIL: swift_test_mode_optimize_size
+// XFAIL: swift_test_mode_optimize_unchecked
+
 import StdlibUnittest
 import DifferentiationUnittest