Update to 2.40.0

Conflicts:
	doc/releasenotes.html
	vaadin-testbench-standalone/lib/org/seleniumhq/selenium/selenium-standalone/maven-metadata-local.xml
	vaadin-testbench/pom.xml
	vaadin-testbench/src/test/java/com/vaadin/testbench/commands/TestBenchCommandExecutorTest.java

Change-Id: I386b029518a137fb0cfb4e47d6a97177997d5fc0