fix(migrations): Skip pg_dumpall restrict/unrestrict tokens in drift check

PostgreSQL 16+ emits \restrict and \unrestrict directives with random
per-session tokens in pg_dumpall output. These tokens differ between
any two dumps and are unrelated to the database schema, causing the
migration drift detection to always report false positives.

Filter out these lines in the norm() function alongside the existing
filters for comments and django_migrations tables.

Co-Authored-By: Claude Opus 4 <noreply@anthropic.com>

Author: vgrozdanic

tools/migrations/compare.py

@@ -39,6 +39,10 @@ def norm(s: str) -> dict[str, str]:
             _, db = line.split()
         if line.startswith("--"):
             continue
+        # pg_dumpall (PostgreSQL 16+) emits \restrict / \unrestrict with
+        # random per-session tokens.  These are not part of the schema.
+        if line.startswith(r"\restrict ") or line.startswith(r"\unrestrict "):
+            continue
         if last == "\n" and line == "\n":
             continue
         else: