CI: github: add DEBUG_STRICT=2 to ASAN jobs

Add an DEBUG_STRICT=2 option to the ASAN jobs in order to trigger the
BUG_ON_HOT() conditions.

Author: wlallemand

.github/matrix.py

@@ -207,6 +207,7 @@ def main(ref_name):
                         'OPT_CFLAGS="-O1"',
                         "USE_ZLIB=1",
                         "USE_OT=1",
+                        "DEBUG=-DDEBUG_STRICT=2",
                         "OT_INC=${HOME}/opt-ot/include",
                         "OT_LIB=${HOME}/opt-ot/lib",
                         "OT_RUNPATH=1",