Update github actions yaml (#10)

Author: andys8

.github/workflows/ci.yml

@@ -10,14 +10,14 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: purescript-contrib/setup-purescript@main
-      - uses: actions/setup-node@v2
+      - uses: actions/setup-node@v4
         with:
-          node-version: "16"
+          node-version: "20"
 
       - name: Cache PureScript dependencies
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           key: ${{ runner.os }}-spago-${{ hashFiles('**/*.dhall') }}
           path: |