[analyzer] Disable a flaky test while triaging why its flaky

I had previous attempts for fixing this flaky test.
Let's admit I failed so far, and disable this until we have a permanent
fix.

See the discussion at:
llvm#126913 (comment)

Author: steakhal

clang/test/Analysis/live-stmts.cpp

@@ -1,3 +1,6 @@
+// Disabling this flaky test, see https://github.com/llvm/llvm-project/pull/126913#issuecomment-2655850766
+// UNSUPPORTED: *
+
 // RUN: %clang_analyze_cc1 -w -analyzer-checker=debug.DumpLiveExprs %s 2>&1\
 // RUN:   | FileCheck %s