test: disable unasserted performance benchmarks in CPArray suites

Prefix unasserted performance tests with 'disabled_' in CPArrayControllerTest
and CPArrayPerformanceTest to eliminate wall-clock timing noise from standard
CI runs.

Add a dummy assertion to CPArrayPerformanceTest to maintain runner
compatibility without executing obsolete micro-benchmarks.

Tests/AppKit/CPArrayControllerTest.j

@@ -1125,8 +1125,14 @@
 /*!
     Test the speed of set an big array when the old was an empty.
     Also test the speed when an empty array is set and the old is an big
+
+    Disabled: This method is a macro-benchmark lacking functional assertions.
+    Absolute wall-clock timings are non-deterministic across disparate CI environments
+    and pollute standard test output. Actionable performance tracking requires a
+    dedicated metrics harness. Retained only for ad-hoc local profiling.
 */
-- (void)testPerformance
+
+- (void)disabled_testPerformance
 {
     [self initControllerWithContentBinding];