ci: Update to v2 workflow.

Author: milesj

.github/workflows/build.yml

@@ -14,7 +14,7 @@ jobs:
       fail-fast: true
     steps:
       - uses: actions/checkout@v2
-      - uses: actions/setup-node@v2-beta
+      - uses: actions/setup-node@v2
         with:
           node-version: ${{ matrix.node-version }}
       - run: yarn install --ignore-engines --frozen-lockfile

.github/workflows/pr.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - uses: actions/setup-node@v2-beta
+      - uses: actions/setup-node@v2
       - run: yarn install
       - uses: beemojs/conventional-pr-action@v2
         with: