Update CI to use the new 1.1.x branch

This commit updates the Concourse CI pipeline to use the new 1.1.x
branch for this generation, as the main branch is now dedicated to 1.2.x
features.

Author: bclozel

ci/parameters.yml

@@ -2,7 +2,7 @@ github-repo: "https://github.com/spring-projects/spring-graphql.git"
 github-repo-name: "spring-projects/spring-graphql"
 docker-hub-organization: "springci"
 artifactory-server: "https://repo.spring.io"
-branch: "main"
+branch: "1.1.x"
 milestone: "1.1.x"
 build-name: "spring-graphql"
 pipeline-name: "spring-graphql"