Bump actions/download-artifact from 1 to 4.1.7 in /.github/workflows

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 1 to 4.1.7.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](https://github.com/actions/download-artifact/compare/v1...v4.1.7)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/autobuild.yaml

@@ -101,7 +101,7 @@ jobs:
     if: always() && (needs.schedule_environment.result == 'success' || needs.workflow_dispatch_environment.result == 'success')
     steps:
     - name: Fetch environment variables
-      uses: actions/download-artifact@v1
+      uses: actions/download-artifact@v4.1.7
       with:
         name:
           env
@@ -241,12 +241,12 @@ jobs:
 
         ninja -C grpc-build install
     - name: Fetch target commit
-      uses: actions/download-artifact@v1
+      uses: actions/download-artifact@v4.1.7
       with:
         name:
           env
     - name: Fetch release info
-      uses: actions/download-artifact@v1
+      uses: actions/download-artifact@v4.1.7
       with:
         name:
           release
@@ -339,7 +339,7 @@ jobs:
     if: always() && needs.build.result == 'success'
     steps:
     - name: Fetch release info
-      uses: actions/download-artifact@v1
+      uses: actions/download-artifact@v4.1.7
       with:
         name:
           release