Merge pull request #3309 from o1-labs/cache-ws-crates

CI: cache workspace crates, as some libraries are not often updated

Author: dannywillems

.github/actions/toolchain-shared/action.yml

@@ -35,6 +35,8 @@ runs:
       uses: Swatinem/rust-cache@v2
       with:
         shared-key: ${{ steps.toolchain.outputs.cachekey }}-${{ inputs.targets }}
+        # Some libraries are not often updated.
+        cache-workspace-crates: true
     - if: ${{ inputs.cache == 'true' && inputs.targets == '' }}
       uses: Swatinem/rust-cache@v2
       with: