[threads] Ignore shared-array.wast in fuzzer initial contents (#6706)

Author: tlively

scripts/fuzz_opt.py

@@ -355,6 +355,7 @@ def is_git_repo():
     'shared-types.wast',
     'shared-polymorphism.wast',
     'shared-struct.wast',
+    'shared-array.wast',
 ]