chore: structure action as expected

Author: vmx

.github/actions/proof-params-download.yml renamed to .github/actions/proof-params-download/action.yml

@@ -191,7 +191,7 @@ jobs:
       #  run: ls -al /var/tmp/filecoin-proof-parameters/
 
       - name: Download the proof params
-        uses: ./.github/actions/proof-params-download.yml
+        uses: ./.github/actions/proof-params-download
         #with:
         #  parameters-json-hash: ${{ hashFiles('filecoin-proofs/parameters.json') }}