GitHub: Update to actions/checkout@v4

... to silence deprecation warning regarding Node.js 16 actions.

.github/workflows/build.yml

@@ -17,7 +17,7 @@ jobs:
         run: |
           echo "BRANCH=${GITHUB_BASE_REF:-${GITHUB_REF#refs/heads/}}" >$GITHUB_ENV
       - name: Check out code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Set up build
         run: |
           mkdir -p $HOME/src/ljt.nightly
@@ -46,7 +46,7 @@ jobs:
         run: |
           echo "BRANCH=${GITHUB_BASE_REF:-${GITHUB_REF#refs/heads/}}" >$GITHUB_ENV
       - name: Check out code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Set up build
         run: |
           brew install yasm md5sha1sum
@@ -68,7 +68,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Set up build
         run: |
           sudo apt install -y nasm
@@ -91,7 +91,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Build
         env:
           CTEST_OUTPUT_ON_FAILURE: 1
@@ -110,7 +110,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Set up build
         run: |
           sudo apt update
@@ -136,7 +136,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Set up build
         run: |
           sudo apt -y install nasm
@@ -161,7 +161,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Build
         env:
           CTEST_OUTPUT_ON_FAILURE: 1