ci: use 'actions/checkout@v3' in favor of 'actions/checkout@v2'

Author: mroavi

.github/workflows/CI.yml

@@ -25,7 +25,7 @@ jobs:
         arch:
           - x64
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: julia-actions/setup-julia@v1
         with:
           version: ${{ matrix.version }}

.github/workflows/documentation.yml

@@ -15,7 +15,7 @@ jobs:
       contents: write
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: julia-actions/setup-julia@latest
         with:
           version: '1'