Update GitHub CI rules.

Author: michaelrsweet

.github/workflows/build.yml

@@ -14,7 +14,7 @@ jobs:
 
     steps:
     - name: Checkout libcups
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         submodules: recursive
     - name: Update Build Environment
@@ -50,7 +50,7 @@ jobs:
 
     steps:
     - name: Checkout libcups
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         submodules: recursive
     - name: Update Build Environment
@@ -86,7 +86,7 @@ jobs:
 
     steps:
     - name: Checkout libcups
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         submodules: recursive
     - name: Configure libcups
@@ -113,7 +113,7 @@ jobs:
 
     steps:
     - name: Checkout libcups
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         submodules: recursive
     - name: Setup msbuild

.github/workflows/codeql-analysis.yml

@@ -24,7 +24,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: recursive
 

.github/workflows/coverity.yml

@@ -8,7 +8,7 @@ jobs:
     environment: Coverity
     steps:
       - name: Checkout libcups
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: recursive
       - name: Update Build Environment