Create isolated tmp dir for konflux e2e tests

Signed-off-by: Oliver Walsh <owalsh@redhat.com>

Author: olliewalsh

.tekton/integration/tasks/test-vm-cmd.yaml

@@ -111,12 +111,16 @@ spec:
         EXTRA_ARGS+=("-v" "/tmp/nvidia.yaml:/etc/cdi/nvidia.yaml")
       fi
       podman pull $TEST_IMAGE
+
+      TEMP_DIR=$(mktemp -d -p /var/tmp e2e-test.XXXXXX)
+      trap 'rm -rf "$TEMP_DIR"' EXIT
+
       podman run \
       --userns=keep-id \
       --security-opt label=disable \
       --security-opt unmask=/proc/* \
       --device /dev/net/tun \
-      -v /var/tmp:/tmp \
+      -v "${TEMP_DIR}":/tmp \
       \${EXTRA_ARGS[*]} \
       ${PODMAN_ENV[*]} \
       $TEST_IMAGE $TEST_CMD