tests: get epochs/daily commit with ./wpt rev-list (denoland#11002)

.github/workflows/wpt_epoch.yml

@@ -50,7 +50,7 @@ jobs:
  run: |
  git remote set-branches origin '*'
  git fetch origin
- git checkout origin/epochs/daily
+ git checkout $(./wpt rev-list --epoch 1d)
  git checkout -b epochs/daily
 
  - name: Configure hosts file for WPT (unix)