ci: Report wheel sizes

.github/workflows/benchmark.yml

@@ -73,6 +73,50 @@ jobs:
         working-directory: py-polars
         run: maturin develop --release -- -C codegen-units=8 -C lto=thin -C target-cpu=native
 
+      - name: Set wheel size
+        run: |
+          WHEEL_SIZE=$(ls -l polars/polars*.so | awk '{ print $5 }')
+          echo "WHEEL_SIZE=$WHEEL_SIZE" >> $GITHUB_ENV
+
+      - name: Upload wheel sizes artifact (main only)
+        if: github.ref_name == 'main'
+        uses: actions/upload-artifact@v3
+        with:
+          name: wheel-size
+          path: |
+            echo "$GITHUB_RUN_ID $WHEEL_SIZE" > wheel_sizes.txt
+            wheel_sizes.txt
+
+      - name: Download main wheel size
+        uses: actions/download-artifact@v3
+        with:
+          name: wheel-size
+        continue-on-error: true 
+
+      - name: Extract previous wheel size
+        id: load_previous_size
+        run: |
+          if [[ -f wheel_sizes.txt ]]; then
+            PREVIOUS_WHEEL_SIZE=$(tail -n 1 wheel_sizes.txt | awk '{ print $2 }')
+            echo "PREVIOUS_WHEEL_SIZE=$PREVIOUS_WHEEL_SIZE" >> $GITHUB_ENV
+          else
+            echo "PREVIOUS_WHEEL_SIZE=Unknown" >> $GITHUB_ENV
+          fi
+
+      - name: Comment wheel size
+      - uses: actions/github-script@v7
+        with:
+        script: |
+            const previousSize = process.env.PREVIOUS_WHEEL_SIZE || 'Unknown';
+            const currentSize = process.env.CURRENT_WHEEL_SIZE || 'Unknown';
+            github.rest.issues.createComment({
+              issue_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              body: `The previous wheel size was **${previousSize} bytes**.\nThe current wheel size after this PR is **${currentSize} bytes**.`
+            })
+
+
       - name: Run benchmark tests
         uses: CodSpeedHQ/action@v3
         with:
@@ -87,4 +131,4 @@ jobs:
         working-directory: py-polars
         env:
           POLARS_AUTO_NEW_STREAMING: 1
-        run: pytest -n auto --dist loadgroup -m "not may_fail_auto_streaming and not slow and not write_disk and not release and not docs and not hypothesis and not benchmark and not ci_only"
+        run: pytest -n auto --dist loadgroup -m "not may_fail_auto_streaming and not slow and not write_disk and not release and not docs and not hypothesis and not benchmark and not ci_only"