ci: Do not show output of failed tests at the end too (#43449)

This reverts #39643, effectively

For the record, @SomeoneToIgnore found it quite cumbersome to scroll
through logs just to see which tests have failed. I kinda see the
argument. At the same time, I wish nextest could do both: it could
aggregate logs of failed tests and then print out the summary.

Release Notes:

- N/A

.github/workflows/extension_tests.yml

@@ -77,7 +77,7 @@ jobs:
       uses: taiki-e/install-action@nextest
     - name: steps::cargo_nextest
       if: inputs.run_tests
-      run: cargo nextest run --workspace --no-fail-fast --failure-output immediate-final
+      run: cargo nextest run --workspace --no-fail-fast
       shell: bash -euxo pipefail {0}
     timeout-minutes: 3
   check_extension: