chore: refactor workflow writting (#2225)

# What does this PR do?

Use a composite action to avoid similar steps repetitions and
centralization of the defaults.

Signed-off-by: Sébastien Han <seb@redhat.com>

.github/workflows/test-external-providers.yml

@@ -25,15 +25,8 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
-      - name: Install uv
-        uses: astral-sh/setup-uv@6b9c6063abd6010835644d4c2e1bef4cf5cd0fca # v6.0.1
-        with:
-          python-version: "3.10"
-
-      - name: Set Up Environment and Install Dependencies
-        run: |
-          uv sync --extra dev --extra test
-          uv pip install -e .
+      - name: Install dependencies
+        uses: ./.github/actions/setup-runner
 
       - name: Apply image type to config file
         run: |
@@ -59,7 +52,6 @@ jobs:
         env:
           INFERENCE_MODEL: "meta-llama/Llama-3.2-3B-Instruct"
         run: |
-          source ci-test/bin/activate
           uv run pip list
           nohup uv run --active llama stack run tests/external-provider/llama-stack-provider-ollama/run.yaml --image-type ${{ matrix.image-type }} > server.log 2>&1 &