ci: bump checkout and setup-python to fix Node 20 deprecation

GitHub Actions runners are dropping Node 20 support, forcing actions
pinned to it onto Node 24 with a deprecation warning. Bump
actions/checkout to v7 and actions/setup-python to v6 in the build and
deploy workflows to versions that target current Node natively.

Part of LITE-33583.

Author: pcaro

.github/workflows/build.yml

@@ -17,11 +17,11 @@ jobs:
         python-version: ['3.10', '3.11', '3.12']
     steps:
     - name: Checkout
-      uses: actions/checkout@v3
+      uses: actions/checkout@v7
       with:
         fetch-depth: 0
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v6
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies
@@ -41,11 +41,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v7
         with:
           fetch-depth: 0
       - name: Set up Python '3.10.0'
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v6
         with:
           python-version: '3.10'
       - name: Install dependencies

.github/workflows/deploy.yml

@@ -8,9 +8,9 @@ jobs:
   deploy:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v7
     - name: Set up Python
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v6
       with:
         python-version: '3.10'
     - name: Install dependencies