Update CI config

Author: novemberborn

.github/workflows/ci.yml

@@ -2,7 +2,7 @@ name: Install and test @ava/cooperate
 on:
   push:
     branches:
-    - master
+    - main
   pull_request:
     paths-ignore:
     - '*.md'
@@ -15,15 +15,13 @@ jobs:
       matrix:
         node-version: [^12.22, ^14.17, ^16.4, ^17]
     steps:
-      - uses: actions/checkout@v1
-        with:
-          fetch-depth: 1
-      - uses: actions/setup-node@v1
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v2
         with:
           node-version: ${{ matrix.node-version }}
       - run: npm install --no-audit
       - run: npm test
-      - uses: codecov/codecov-action@v1
+      - uses: codecov/codecov-action@v2
         with:
           file: coverage/lcov.info
           name: ${{ matrix.node-version }}