ci/datapath-verifier: Don't overwrite artifacts between jobs

In the tests-datapath-verifier workflow, all jobs generated from the
matrix (for running the tests with different kernel versions) upload
files to the same artifact on failure. This means that a job may
overwrite the upload from a previous job, and in the end we only get the
uploads from the last job to complete. If several jobs fail with
different errors, then we lose useful debugging information.

Let's have the jobs upload their files to separate artifacts, named
after the kernel version in use.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>

.github/workflows/tests-datapath-verifier.yaml

@@ -230,7 +230,7 @@ jobs:
         if: ${{ !success() }}
         uses: actions/upload-artifact@0b7f8abb1508181956e8e162db84b466c27e18ce # v3.1.2
         with:
-          name: datapath-verifier
+          name: datapath-verifier_${{ matrix.kernel }}
           path: datapath-verifier
           retention-days: 5