bust CI cache

Author: Juliette Pretot

.github/workflows/ci.yaml

@@ -64,7 +64,7 @@ jobs:
         uses: actions/cache@v2
         env:
           # Increment this value to invalidate previous cache entries.
-          CACHE_VERSION: 2
+          CACHE_VERSION: 3
         with:
           path: |
             ./cargo-cache/bin