ci: retry Python system dependency installation

Refresh APT indexes before each retry to recover from transient mirror
404s. Stop after three failed attempts and preserve the failure status.

Co-Authored-By: Codex <noreply@anthropic.com>
AI-Model: gpt-6
Co-Authored-By: Codex <noreply@ai-tool.com>
AI-Contributed/Feature: 25/25
AI-Contributed/UT: 0/0

Author: 3 people

.github/workflows/paimon-python-checks.yml

@@ -69,15 +69,22 @@ jobs:
       - name: Install system dependencies
         shell: bash
         run: |
-          apt-get update && apt-get install -y \
-            build-essential \
-            git \
-            curl \
-            pkg-config \
-            libssl-dev \
-            libclang-dev \
-            && apt-get clean \
-            && rm -rf /var/lib/apt/lists/*
+          # Refresh indexes on retry as well: mirrors can briefly return 404 for packages.
+          for attempt in 1 2 3; do
+            if apt-get update && apt-get install -y \
+              build-essential \
+              git \
+              curl \
+              pkg-config \
+              libssl-dev \
+              libclang-dev; then
+              break
+            fi
+            [ "$attempt" -lt 3 ] || exit 1
+            sleep 10
+          done
+          apt-get clean
+          rm -rf /var/lib/apt/lists/*
 
       - name: Verify Java and Maven installation
         run: |