[ci][bug] remove "cache: 'pip'" from python setup to avoid post python setup failure (#2073)

^

also adds cache to skyrl cpu test

Author: erictang000

.github/workflows/cpu_skyrl.yaml

@@ -37,8 +37,12 @@ jobs:
     steps:
     - uses: actions/checkout@v4
     - name: Install uv
-      run: |
-        curl -LsSf https://astral.sh/uv/install.sh | sh
+      # Use the action rather than the curl installer: on GitHub-hosted runners it
+      # also restores/saves ~/.cache/uv between runs, which matters here because
+      # this job resolves several distinct extra sets (tinker/jax/dev).
+      uses: astral-sh/setup-uv@v6
+      with:
+        enable-cache: true
     - name: Run lint
       run: |
         # Pin to match the ruff rev in .pre-commit-config.yaml. Unpinned `uvx ruff`

.github/workflows/cpu_skyrl_train.yaml

@@ -42,7 +42,6 @@ jobs:
         with:
           # Semantic version range syntax or exact version of a Python version
           python-version: '3.12'
-          cache: 'pip'
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@v6
         with:
@@ -64,7 +63,6 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: '3.12'
-          cache: 'pip'
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@v6
         with:
@@ -88,7 +86,6 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: '3.12'
-          cache: 'pip'
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@v6
         with:

.github/workflows/gpu_ci_h100.yaml

@@ -52,7 +52,6 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: '3.12'
-          cache: 'pip'
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@v6
         with:

.github/workflows/gpu_e2e_ci.yaml

@@ -26,7 +26,6 @@ jobs:
         with:
           # Semantic version range syntax or exact version of a Python version
           python-version: '3.12'
-          cache: 'pip'
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@v6
         with:

.github/workflows/gpu_e2e_ci_fully_async.yaml

@@ -26,7 +26,6 @@ jobs:
         with:
           # Semantic version range syntax or exact version of a Python version
           python-version: '3.12'
-          cache: 'pip'
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@v6
         with:

.github/workflows/gpu_e2e_ci_megatron.yaml

@@ -26,7 +26,6 @@ jobs:
         with:
           # Semantic version range syntax or exact version of a Python version
           python-version: '3.12'
-          cache: 'pip'
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@v6
         with:

.github/workflows/gpu_e2e_ci_sft.yaml

@@ -26,7 +26,6 @@ jobs:
         with:
           # Semantic version range syntax or exact version of a Python version
           python-version: '3.12'
-          cache: 'pip'
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@v6
         with:

.github/workflows/gpu_e2e_ci_tinker.yaml

@@ -26,7 +26,6 @@ jobs:
         with:
           # Semantic version range syntax or exact version of a Python version
           python-version: '3.12'
-          cache: 'pip'
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@v6
         with:

.github/workflows/gpu_e2e_ci_tinker_fully_async.yaml

@@ -26,7 +26,6 @@ jobs:
         with:
           # Semantic version range syntax or exact version of a Python version
           python-version: '3.12'
-          cache: 'pip'
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@v6
         with:

.github/workflows/gpu_skyrl.yaml

@@ -40,7 +40,6 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: '3.12'
-          cache: 'pip'
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@v6
         with: