Revert "github workflows: ensure ${env.wc} exists."

This reverts commit 6078cdf.

This is not the right place to do this, and this wasn't the actual
root cause of the CI failures.

Author: silentbicycle

.github/workflows/ci.yml

@@ -16,8 +16,6 @@ jobs:
   checkout:
     name: "Checkout"
     runs-on: ubuntu-22.04
-    run: |
-      mkdir -p ${{ env.wc }}
 
     steps:
     - name: Cache checkout