.sync/workflows/leaf/codeql-platform.yml: Bump actions/checkout to v4 (#240)

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to
4 in this leaf workflow.

Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>

Author: makubacki

.sync/workflows/leaf/codeql-platform.yml

@@ -41,7 +41,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Install Python
       uses: actions/setup-python@v4
@@ -124,7 +124,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Install Python
       uses: actions/setup-python@v4