Update test-system.md (#304)

docs/topics/test-system.md

@@ -41,7 +41,7 @@ Normally `example-full` is the environment you want to use. The folder should co
 docker-compose -f docker-compose.yml -f docker-compose.extra.yml down
 ```
 
-### 2. Update image version and source variables to shell
+### 2. Update image version in .env file
 
 Example for workflow run [1157808966](https://github.com/wmde/wikibase-release-pipeline/actions/runs/1157808966).
 
@@ -56,17 +56,6 @@ WDQS_PROXY_IMAGE_NAME=ghcr.io/wmde/wdqs-proxy:1157808966
 MYSQL_IMAGE_NAME=mariadb:10.3
 ```
 
-Source the updated `.env` file with the new variables 
-```sh
-$ set -o allexport; source .env; set +o allexport
-```
-
-Optionally confirm that it worked by echoing the variable
-
-```sh
-$ echo $WIKIBASE_IMAGE_NAME
-```
-
 ### 3. start containers again 
 
 ```sh