MAINT: Updated tests for newer MariaDB version.

Makefile

@@ -59,23 +59,22 @@ test:
 test-dump-update:
 	pytest dump_updates
 
-# Run tests with a database which is started in a Docker container
+# Run tests with a database which is started in a MariaDB Docker container
 .PHONY: test-docker
 test-docker:
 	@docker kill caosdb-mysqlserver-test || true
-	@docker container rm caosdb-mysqlserver-test || true
+	@docker container rm -v caosdb-mysqlserver-test || true
 	@docker run --name caosdb-mysqlserver-test -p "3306:3306" \
-		-e MYSQL_ROOT_PASSWORD="pass-for-test" -d mariadb
+		-e MYSQL_ROOT_PASSWORD="pass-for-test" -d mariadb:10.11
 	@sleep 10
 	MAINPATH=$(realpath tests/docker_env) utils/make_db test --fresh
-	@docker kill caosdb-mysqlserver-test
-	@docker container rm caosdb-mysqlserver-test
+	make test-docker-stop
 
 # if automatic stopping failed
 .PHONY: test-docker-stop
 test-docker-stop:
 	docker kill caosdb-mysqlserver-test
-	docker container rm caosdb-mysqlserver-test
+	docker container rm -v caosdb-mysqlserver-test
 
 # Compile the standalone documentation
 .PHONY: doc