fix(ci): prevent Test Reporter from aggregating stale test results (kroxylicious#3805)

The Test Reporter action was configured to download artifacts by name,
which caused it to aggregate test results from multiple workflow runs
instead of just the current run. When artifact names are reused across
runs, the action downloads all matching artifacts from the repository
history, leading to false positives from stale test failures.

Changed to read test results directly from the local filesystem
(kroxylicious-systemtests/target/surefire-reports/**/TEST-*.xml)
instead of downloading the artifact that was just uploaded in the
same job.

This ensures only current test results are reported, eliminating
false failures from previous runs.

Assisted-by: Claude Sonnet 4.5 <noreply@anthropic.com>

Signed-off-by: Keith Wall <kwall@apache.org>

Author: k-wall

.github/workflows/run-system-tests.yaml

@@ -200,9 +200,8 @@ jobs:
         uses: dorny/test-reporter@a43b3a5f7366b97d083190328d2c652e1a8b6aa2
         if: ${{ !cancelled() }}
         with:
-          artifact: junit-results-${{ matrix.tests }}-${{ inputs.kafkaClient }}
           name: SystemTests-${{ matrix.tests }}-${{ inputs.kafkaClient }}
-          path: '*.xml'
+          path: 'kroxylicious-systemtests/target/surefire-reports/**/TEST-*.xml'
           reporter: java-junit
           fail-on-empty: 'false'