Remove gcr.io location

* explained in: https://blog.paketo.io/posts/paketo-gcr-registry-sunset/

Author: anthonydahanne

.github/pipeline-descriptor.yml

@@ -10,14 +10,11 @@ helpers:
   "bin/helper": "$GOMOD/cmd/helper"
 
 package:
-  repositories:   ["docker.io/paketobuildpacks/spring-boot","gcr.io/paketo-buildpacks/spring-boot"]
+  repositories:   ["docker.io/paketobuildpacks/spring-boot"]
   register:       true
   registry_token: ${{ secrets.PAKETO_BOT_GITHUB_TOKEN }}
 
 docker_credentials:
-- registry: gcr.io
-  username: _json_key
-  password: ${{ secrets.GCR_PUSH_BOT_JSON_KEY }}
 - registry: docker.io
   username: ${{ secrets.PAKETO_BUILDPACKS_DOCKERHUB_USERNAME }}
   password: ${{ secrets.PAKETO_BUILDPACKS_DOCKERHUB_PASSWORD }}

README.md

@@ -1,4 +1,4 @@
-# `gcr.io/paketo-buildpacks/spring-boot`
+# `paketobuildpacks/spring-boot`
 The Paketo Buildpack for Spring Boot is a Cloud Native Buildpack that contributes Spring Boot dependency information and slices an application into multiple layers.
 
 ## Behavior