Bump release-docker actions to Node 24

Move checkout, upload-artifact, and download-artifact to their current majors so the release image build stops relying on the deprecated Node 20 runtime. Docker actions are left as-is (not flagged). Only runs on release tags, so it is not exercised by PR CI.

.github/workflows/release-docker.yml

@@ -36,7 +36,7 @@ jobs:
           platform: ${{ matrix.platform }}
 
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v7
 
       - name: Docker metadata (labels)
         id: meta
@@ -76,7 +76,7 @@ jobs:
           touch "${{ runner.temp }}/digests/${digest#sha256:}"
 
       - name: Upload digest
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: digests-${{ env.PLATFORM_PAIR }}
           path: ${{ runner.temp }}/digests/*
@@ -92,7 +92,7 @@ jobs:
       packages: write
     steps:
       - name: Download digests
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v7
         with:
           path: ${{ runner.temp }}/digests
           pattern: digests-*