fix: codeql check

Author: irtazaakram

xmodule/capa_block.py

@@ -2507,7 +2507,7 @@ def randomization_bin(seed, problem_id):
     interesting.  To avoid having sets of students that always get the same problems,
     we'll combine the system's per-student seed with the problem id in picking the bin.
     """
-    r_hash = hashlib.sha1()
+    r_hash = hashlib.sha256()
     r_hash.update(str(seed).encode())
     r_hash.update(str(problem_id).encode())
     # get the first few digits of the hash, convert to an int, then mod.