analyze_outcome: work around old Python in CI

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/tests/scripts/analyze_outcomes.py b/tests/scripts/analyze_outcomes.py
index a5340bd..a0127be 100755
--- a/tests/scripts/analyze_outcomes.py
+++ b/tests/scripts/analyze_outcomes.py
@@ -100,7 +100,9 @@
     - If the pattern is a string, name must be equal to match.
     - If the pattern is a regex, name must fully match.
     """
-    if isinstance(str_or_re, re.Pattern):
+    # The CI's python is too old for re.Pattern
+    #if isinstance(str_or_re, re.Pattern):
+    if not isinstance(str_or_re, str):
         if str_or_re.fullmatch(name):
             return True
     else: