Update mypy_primer workflow (#17987)

Update the mypy_primer workflow to use actions/upload-artifact@v4.
https://github.com/actions/upload-artifact/tree/v4

Author: cdce8p

.github/workflows/mypy_primer.yml

@@ -69,18 +69,35 @@ jobs:
             --output concise \
             | tee diff_${{ matrix.shard-index }}.txt
           ) || [ $? -eq 1 ]
-      - name: Upload mypy_primer diff
-        uses: actions/upload-artifact@v3
-        with:
-          name: mypy_primer_diffs
-          path: diff_${{ matrix.shard-index }}.txt
-      - if: ${{ matrix.shard-index }} == 0
+      - if: ${{ matrix.shard-index == 0 }}
         name: Save PR number
         run: |
           echo ${{ github.event.pull_request.number }} | tee pr_number.txt
-      - if: ${{ matrix.shard-index }} == 0
-        name: Upload PR number
-        uses: actions/upload-artifact@v3
+      - if: ${{ matrix.shard-index == 0 }}
+        name: Upload mypy_primer diff + PR number
+        uses: actions/upload-artifact@v4
+        with:
+          name: mypy_primer_diffs-${{ matrix.shard-index }}
+          path: |
+            diff_${{ matrix.shard-index }}.txt
+            pr_number.txt
+      - name: Upload mypy_primer diff
+        uses: actions/upload-artifact@v4
+        if: ${{ matrix.shard-index != 0 }}
+        with:
+          name: mypy_primer_diffs-${{ matrix.shard-index }}
+          path: diff_${{ matrix.shard-index }}.txt
+
+  join_artifacts:
+    name: Join artifacts
+    runs-on: ubuntu-latest
+    needs: [mypy_primer]
+    permissions:
+      contents: read
+    steps:
+      - name: Merge artifacts
+        uses: actions/upload-artifact/merge@v4
         with:
           name: mypy_primer_diffs
-          path: pr_number.txt
+          pattern: mypy_primer_diffs-*
+          delete-merged: true

.github/workflows/mypy_primer_comment.yml

@@ -18,7 +18,7 @@ jobs:
     if: ${{ github.event.workflow_run.conclusion == 'success' }}
     steps:
       - name: Download diffs
-        uses: actions/github-script@v6
+        uses: actions/github-script@v7
         with:
           script: |
             const fs = require('fs');