ignore safety's own nltk vulnerability (pyupio/safety#742)

Author: fmigneault

.safety-policy.yml

@@ -22,6 +22,12 @@ security: # configuration for the `safety check` command
               false positive
               safety's own 'marshmallow' dependency that is not a vulnerability
               https://github.com/pyupio/safety/issues/826
+        "SFTY-20260616-58930":
+            reason:
+              false positive
+              safety's own 'nltk' dependency that is not a vulnerability
+              CVE-2026-54293
+              https://github.com/pyupio/safety/issues/742
         "SFTY-20250331-30014":
             reason: |
               'torch==2.10' CPU/GPU variants