Bump x509-limbo and/or wycheproof in CI (#13716)

Co-authored-by: pyca-boringbot[bot] <pyca-boringbot[bot][email protected]>

Author: pyca-boringbot[bot]

.github/actions/fetch-vectors/action.yml

@@ -17,6 +17,6 @@ runs:
       with:
         repository: "C2SP/x509-limbo"
         path: "x509-limbo"
-        # Latest commit on the x509-limbo main branch, as of Oct 14, 2025.
-        ref: "f6e2b935b3069434172f9f9e2369cc6d0ebb12bc" # x509-limbo-ref
+        # Latest commit on the x509-limbo main branch, as of Oct 21, 2025.
+        ref: "ee8aef6646ff60f4b7bc7f576493a58995d62c25" # x509-limbo-ref
         persist-credentials: false