Update GitHub checkout action to v5

Author: petk

.github/workflows/check.yaml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           fetch-depth: 2
 

.github/workflows/ci.yaml

@@ -110,7 +110,7 @@ jobs:
             sendmail;
 
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           fetch-depth: 2
 
@@ -142,7 +142,7 @@ jobs:
     name: Windows
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           fetch-depth: 2