[TASK] Minor README.md update

docker-images/README.md

@@ -40,11 +40,6 @@ which executes karma javascript tests using chrome. Since this image is quite bi
 separated from the default `core-testing-js` image to only use it when needed.
 
 
-### core-testing-js-node8
-
-Similar to the js image above, but with older node versions, used for TYPO3 Core v9 js testing.
-
-
 ### core-testing-mssql2019
 
 While we use the official docker images of mysql, mariadb and postgres for tests that rely