☕ Upgrade actions/checkout to v3

To avoid Node.js 12 actions are deprecated warnings

Author: lambdalisue

.github/workflows/test.yml

@@ -39,7 +39,7 @@ jobs:
     steps:
       - run: git config --global core.autocrlf false
         if: runner.os == 'Windows'
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: denoland/setup-deno@v1
         with:
           deno-version: "${{ matrix.version }}"
@@ -75,10 +75,10 @@ jobs:
     steps:
       - run: git config --global core.autocrlf false
         if: runner.os == 'Windows'
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
         with:
           path: "./repo"
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
         with:
           repository: "vim-denops/denops.vim"
           path: "./denops.vim"

.github/workflows/udd.yml

@@ -9,7 +9,7 @@ jobs:
   udd:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: denoland/setup-deno@v1
         with:
           deno-version: "1.x"