ci: add step with killing tarantool after tests

There were still tarantool processes running after all tests were completed.
After the patch all not killed instances of tarantool will be killed in CI
pipeline.

.github/workflows/full-ci.yml

@@ -206,6 +206,12 @@ jobs:
           ETCD_TT_BIN=${ETCD_PATH}etcd;
           pkill -SIGINT -f ${ETCD_TT_BIN} || true
 
+      - name: Kill tarantool, if it was left
+        if: always()
+        run: |
+          TARANTOOL_BIN=${GITHUB_WORKSPACE}/bin/tarantool;
+          pkill -SIGINT -f ${TARANTOOL_BIN} || true
+
   # ee suffix means that the job runs ee integration tests.
   full-ci-macOS-ee:
     if: |