rewrite R2 publishing in Python

Author: zsol

.github/workflows/check.yml

@@ -30,3 +30,11 @@ jobs:
       - name: "Run checks"
         run: |
           ./check.py
+
+      - name: "Run unit tests"
+        run: |
+          uv run python -m unittest tests/test_mirror.py
+
+      - name: "Run mirror integration test"
+        run: |
+          uv run python -m unittest tests/test_mirror_integration.py

.github/workflows/release.yml

@@ -45,6 +45,8 @@ jobs:
           repo: casey/just
           version: 1.42.4
 
+      - uses: astral-sh/setup-uv@e06108dd0aef18192324c70427afc47652e63a82 # v7.5.0
+
       # Perform a release in dry-run mode.
       - run: just release-dry-run ${GH_TOKEN} ${GITHUB_EVENT_INPUTS_SHA} ${GITHUB_EVENT_INPUTS_TAG}
         if: ${{ github.event.inputs.dry-run == 'true' }}