[CI] Update setup-python action to v5 for GHA (#95414)

We currently receive a warning on all Github Actions workflows that use
`setup-python`, since they all use v4 of the action, which uses the
deprecated Node.js 16. This PR upgrades the action in all places to v5,
which uses Node.js 20 (see [setup-python release
page](https://github.com/actions/setup-python/releases/tag/v5.0.0))

.github/workflows/docs.yml

@@ -98,7 +98,7 @@ jobs:
         with:
           fetch-depth: 1
       - name: Setup Python env
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: '3.11'
           cache: 'pip'

.github/workflows/llvm-project-tests.yml

@@ -77,7 +77,7 @@ jobs:
       # lldb.  Using this setup-python action to make 3.10 the default
       # python fixes this.
       - name: Setup Python
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: ${{ inputs.python_version }}
       - name: Install Ninja

.github/workflows/pr-code-format.yml

@@ -56,7 +56,7 @@ jobs:
           clangformat: 17.0.1
 
       - name: Setup Python env
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: '3.11'
           cache: 'pip'

.github/workflows/release-documentation.yml

@@ -37,7 +37,7 @@ jobs:
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
 
       - name: Setup Python env
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           cache: 'pip'
           cache-dependency-path: './llvm/docs/requirements.txt'

.github/workflows/release-doxygen.yml

@@ -39,7 +39,7 @@ jobs:
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
 
       - name: Setup Python env
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           cache: 'pip'
           cache-dependency-path: './llvm/docs/requirements.txt'