Bump downstream dependencies in CI

Author: pyca-boringbot[bot]

.github/workflows/ci.yml

@@ -461,8 +461,8 @@ jobs:
             PATH: certbot
           - DOWNSTREAM: certbot-josepy
             REPO: certbot/josepy
-            # Latest commit on the certbot-josepy main branch, as of Sep 26, 2025.
-            REF: 79050d82bbb38b7f969cf33a536bb56285e0c37a
+            # Latest commit on the certbot-josepy main branch, as of Oct 02, 2025.
+            REF: 31b936ff9b6d1483e34b2f88d0f0d37deb7f9a5e
             PATH: josepy
           - DOWNSTREAM: mitmproxy
             REPO: mitmproxy/mitmproxy
@@ -476,8 +476,8 @@ jobs:
             PATH: scapy
           - DOWNSTREAM: sigstore-python
             REPO: sigstore/sigstore-python
-            # Latest commit on the sigstore-python main branch, as of Oct 01, 2025.
-            REF: b6def062995b3e7ebe528ed68f6c069e85e9956f
+            # Latest commit on the sigstore-python main branch, as of Oct 02, 2025.
+            REF: 0a54b4fce6a26150954c9eea8ed3720af27f06bf
             PATH: sigstore-python
     name: "Downstream tests for ${{ matrix.DOWNSTREAM }}"
     timeout-minutes: 15