Upgrade GitHub actions to the latest versions.

Author: sjrd

.github/workflows/nightly.yml

@@ -17,11 +17,11 @@ jobs:
       SCALA_BRANCH: "${{ matrix.scalabranch }}"
       SCALAJS_BRANCH: "main"
     steps:
-      - uses: actions/checkout@v2
-      - uses: olafurpg/setup-scala@v10
+      - uses: actions/checkout@v3
+      - uses: olafurpg/setup-scala@v14
         with:
           java-version: "[email protected]"
-      - uses: coursier/cache-action@v5
+      - uses: coursier/cache-action@v6
       - name: Node.js version
         run: node -v
       - name: Test