Bump mongo version used for testing

Signed-off-by: Marvin Froeder <[email protected]>

Author: velo

.circleci/config.yml

@@ -292,7 +292,7 @@ jobs:
     working_directory: ~/querydsl
     docker:
       - image: velo/toolchains-4-ci-builds:latest
-      - image: mongo:3.6.1
+      - image: mongo:8.0.9
     steps:
       - checkout
       - restore_cache: