chore: update actions/checkout to v4 (#58)

* chore: update `actions/checkout` to `v4`

* empty commit to rerun CI

Author: vil02

.github/workflows/check_code_format.yml

@@ -14,7 +14,7 @@ jobs:
     name: check format code
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
 

.github/workflows/nim_test.yml

@@ -23,7 +23,7 @@ jobs:
           - '2.0.0'
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - uses: jiro4989/setup-nim-action@v1
         with:

.github/workflows/nim_test_cyclic.yml

@@ -20,7 +20,7 @@ jobs:
           - 'devel'
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - uses: jiro4989/setup-nim-action@v1
         with: