Do not download all artifacts for flaky test detection (#7320)

This is causing 404 failures due to a race condition:
https://github.com/actions/toolkit/issues/1235

It also makes the tests take unnecessarily long.

This was tested by changing a test file and seeing that the flaky test
detection was still working.

.github/workflows/build_and_test.yml

@@ -497,7 +497,6 @@ jobs:
       matrix: ${{ fromJson(needs.prepare_parallelization_matrix_32.outputs.json) }}
     steps:
     - uses: actions/checkout@v3.5.0
-    - uses: actions/download-artifact@v3.0.1
     - uses: "./.github/actions/setup_extension"
     - name: Run minimal tests
       run: |-