ci: upload test failure logs as artifacts

The workflow was only uploading build logs, not test phase failure logs.
This made it impossible to diagnose rootfs and testimage failures.

Now uploads:
- log.do_rootfs.* - Package installation failures
- log.do_testimage.* - Test execution failures
- testresults.json - Test results (if available)

These logs are critical for debugging ptest package installation issues
and test failures.

Related: PR #15252 rootfs failure investigation

Author: rpcme

.github/workflows/build-test-recipe.yml

@@ -303,3 +303,13 @@ jobs:
         with:
           name: ${{ matrix.machine }}-resulttool_report.txt
           path: /home/yoctouser/bitbake-builds/poky-without-meta-aws-poky-distro_poky-altcfg-machine_${{ matrix.machine }}/build/${{ matrix.machine }}-resulttool_report.txt
+      - name: Save test failure logs
+        if: '!cancelled()'
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{ matrix.machine }}-test-logs
+          path: |
+            /home/yoctouser/bitbake-builds/poky-without-meta-aws-poky-distro_poky-altcfg-machine_${{ matrix.machine }}/build/tmp/work/**/temp/log.do_rootfs.*
+            /home/yoctouser/bitbake-builds/poky-without-meta-aws-poky-distro_poky-altcfg-machine_${{ matrix.machine }}/build/tmp/work/**/temp/log.do_testimage.*
+            /home/yoctouser/bitbake-builds/poky-without-meta-aws-poky-distro_poky-altcfg-machine_${{ matrix.machine }}/build/tmp/log/oeqa/testresults.json
+          if-no-files-found: ignore