perform ufuzz on more stable Node.js version

.github/workflows/ufuzz.yml

@@ -17,13 +17,13 @@ jobs:
         shell: bash
         run: |
           git clone --branch v1.5.4 --depth 1 https://github.com/jasongin/nvs.git ~/.nvs
-          while ! timeout 60 bash -c '. ~/.nvs/nvs.sh add 10 && nvs use 10'; do
+          while ! timeout 60 bash -c '. ~/.nvs/nvs.sh add 8 && nvs use 8'; do
             cd ~/.nvs
             while !(git clean -xdf); do echo "'git clean' failed - retrying..."; done
             cd -
           done
           . ~/.nvs/nvs.sh --version
-          nvs use 10
+          nvs use 8
           node --version
           npm config set audit false
           npm config set optional false