build: update actions/checkout version to v4 in workflow files for improved functionality

Author: roboticswithjulia

.github/workflows/rust-minimal.yml

@@ -35,6 +35,8 @@ jobs:
     container:
       image: ${{ matrix.docker_image }}
     steps:
+    - uses: actions/checkout@v4
+    
     - name: Markdown autodocs
       uses: dineshsonachalam/[email protected]
       with:

.github/workflows/rust-stable.yml

@@ -35,6 +35,8 @@ jobs:
     container:
       image: ${{ matrix.docker_image }}
     steps:
+    - uses: actions/checkout@v4
+    
     - name: Markdown autodocs
       uses: dineshsonachalam/[email protected]
       with: