ci: upgrade action-download-artifact

The current version has an artifact poisoning vulnerability - see https://github.com/TinyTapeout/tinytapeout-10/security/dependabot/2 for details

Author: urish

.github/workflows/efabless_tapeout.yaml

@@ -13,7 +13,7 @@ jobs:
 
     steps:
       - name: Download artifact
-        uses: dawidd6/action-download-artifact@v3
+        uses: dawidd6/action-download-artifact@v6
         id: download_artifact
         with:
           workflow: gds.yaml

.github/workflows/precheck.yaml

@@ -38,7 +38,7 @@ jobs:
           pdk_root: ${{ env.PDK_ROOT }}
 
       - name: Download artifact (run id = ${{ github.event.workflow_run.id }})
-        uses: dawidd6/action-download-artifact@v3
+        uses: dawidd6/action-download-artifact@v6
         id: download_artifact
         with:
           workflow: gds.yaml
@@ -122,7 +122,7 @@ jobs:
           pdk_root: ${{ env.PDK_ROOT }}
 
       - name: Download artifact (run id = ${{ github.event.workflow_run.id }})
-        uses: dawidd6/action-download-artifact@v3
+        uses: dawidd6/action-download-artifact@v6
         id: download_artifact
         with:
           workflow: gds.yaml