Update GHA to Python 3 for "testclient.py"

.github/workflows/ci.yml

@@ -15,6 +15,6 @@ jobs:
       - uses: actions/checkout@v3 # clone Notary upstream repo (used for generating necessary certificates to test against)
         with:
           repository: 'notaryproject/notary'
-          ref: '74ee191c214795fb5e839bca841c7be2030d0002'
+          ref: '887a007da8841e49023684656926d79d89d5a9d8'
           path: 'notary-src'
       - run: NOTARY_SOURCE="$GITHUB_WORKSPACE/notary-src" ./.test/test.sh

.test/test.sh

@@ -112,10 +112,9 @@ docker run "${args[@]}" \
 docker run "${args[@]}" \
 	--name notary-testclient \
 	--init \
-	pypy:2.7-bullseye bash -Eeuo pipefail -xc '
+	python:3.10-bullseye bash -Eeuo pipefail -xc '
 		ln -svf ../../fixtures/root-ca.crt cmd/notary/
-		pypy ./buildscripts/testclient.py \
+		python3 ./buildscripts/testclient.py \
 			--reponame registry.local:5000/testclient/testclient \
 			--server "$DOCKER_CONTENT_TRUST_SERVER"
 	'
-# TODO switch to something like "python:3.10-bullseye" once testclient.py actually supports Python 3 🙈