chore(main): release 1.8.0 (#168)

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

Author: release-please[bot]

retail/package.json

@@ -13,7 +13,7 @@
     "test": "c8 mocha"
   },
   "dependencies": {
-    "@google-cloud/retail": "^1.7.0",
+    "@google-cloud/retail": "^1.8.0",
     "@google-cloud/bigquery": "^5.9.2",
     "@google-cloud/storage": "^5.16.1"
   },