Bump GH actions to v4

Author: mikkelfj

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
         run: |
           sudo apt update
           sudo apt install ninja-build
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Build and run tests
         env:
           CC: clang
@@ -26,7 +26,7 @@ jobs:
     name: Ubuntu (make, gcc)
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Build and run tests
         env:
           CC: gcc
@@ -42,7 +42,7 @@ jobs:
       - name: Prepare
         run: |
           brew install cmake ninja
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Build and run tests
         run: |
           scripts/test.sh
@@ -52,7 +52,7 @@ jobs:
     runs-on: windows-2022
     steps:
       - uses: microsoft/[email protected]
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Build and run tests
         run: |
           cmake .