chore(deps): update pin docker digests packages

Author: renovate-bot

.circleci/config.yml

@@ -6,8 +6,8 @@ machine:
 jobs:
   build:
     docker:
-      - image: circleci/node:8
-      - image: circleci/mysql:8.0.3
+      - image: circleci/node:8@sha256:257fdc7e2949a9576e1a96364e0428d461d0505167c70dcc3e6c3825ce8a6557
+      - image: circleci/mysql:8.0.3@sha256:ea4c062323a944b9152137a62f5b2c8b3d5e235d98af66675871506a1bf6cc6e
     environment:
       - NPM_CONFIG_LOGLEVEL: warn
     working_directory: ~/repo