fix(ci): suppress libc++ alloc-dealloc-mismatch false positive in ASan

Add alloc_dealloc_mismatch=0 to ASAN_OPTIONS to suppress known
false positives caused by libc++ internal allocation strategies.
This is a documented ASan/libc++ interaction issue, not a real bug.

Author: kcenon

.github/workflows/ci.yml

@@ -258,7 +258,7 @@ jobs:
       timeout-minutes: 10
       run: |
         cd build
-        export ASAN_OPTIONS=detect_leaks=1
+        export ASAN_OPTIONS=detect_leaks=1:alloc_dealloc_mismatch=0
         export UBSAN_OPTIONS=print_stacktrace=1
         export TSAN_OPTIONS=second_deadlock_stack=1