chore: replace the hard coded branch version (#687) (#692)

Co-authored-by: Manuel Carrasco Moñino <manolo@vaadin.com>

Co-authored-by: Zhe Sun <31067185+ZheSun88@users.noreply.github.com>
Co-authored-by: Manuel Carrasco Moñino <manolo@vaadin.com>

scripts/prepareDeploy.sh

@@ -50,9 +50,13 @@ pomVersion=`cat pom.xml | grep '<version>' | head -1 | cut -d '>' -f2 | cut -d '
 versionBase=`getBaseVersion $version`
 pomBase=`getBaseVersion $pomVersion`
 
+### Get the master branch version for components
+masterPom=`curl -s "https://raw.githubusercontent.com/vaadin/vaadin-flow-components/master/pom.xml"`
+masterMajorMinor=`echo "$masterPom" | grep '<version>' | cut -d '>' -f2 |cut -d '<' -f1 | grep "^$base" | head -1 | cut -d '-' -f1`
+
 ### Load versions file for this platform release
 branch=$versionBase
-[ $branch = "20.0" ] && branch=master
+[ $branch = $masterMajorMinor ] && branch=master
 versions=`curl -s "https://raw.githubusercontent.com/vaadin/platform/$branch/versions.json"`
 [ $? != 0 ] && branch=master && versions=`curl -s "https://raw.githubusercontent.com/vaadin/platform/$branch/versions.json"`