util: Make --with-asan work with more versions of the python lib.

The version of the python library on my system is libpython3.9.so, not
libpython3.so. Generalize the line in lsan-suppressions to cover this
version as well.

Change-Id: Iaee9a7767eb5f735862a3716c796213a43c5f9e5
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/48643
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

util/lsan-suppressions

@@ -1,2 +1,2 @@
 # Suppress detection of leaks from within the python3 interpreter.
-leak:libpython3.so
+leak:libpython3*.so