Update docker_registry2 (#7658)

Need to change digest function used to retain functionality

Co-authored-by: Jurre <jurre@github.com>
Co-authored-by: Jeff Widman <jeff@jeffwidman.com>

common/dependabot-common.gemspec

@@ -30,7 +30,7 @@ Gem::Specification.new do |spec|
   spec.add_dependency "aws-sdk-ecr", "~> 1.5"
   spec.add_dependency "bundler", ">= 1.16", "< 3.0.0"
   spec.add_dependency "commonmarker", ">= 0.20.1", "< 0.24.0"
-  spec.add_dependency "docker_registry2", "~> 1.14.0"
+  spec.add_dependency "docker_registry2", "~> 1.18.0"
   spec.add_dependency "excon", "~> 0.96", "< 0.101"
   spec.add_dependency "faraday", "2.7.4"
   spec.add_dependency "faraday-retry", "2.2.0"

docker/lib/dependabot/docker/update_checker.rb

@@ -245,7 +245,7 @@ def digest_of(tag)
       end
 
       def fetch_digest_of(tag)
-        docker_registry_client.digest(docker_repo_name, tag)&.delete_prefix("sha256:")
+        docker_registry_client.manifest_digest(docker_repo_name, tag)&.delete_prefix("sha256:")
       rescue *transient_docker_errors => e
         attempt ||= 1
         attempt += 1

updater/Gemfile.lock

@@ -18,7 +18,7 @@ PATH
       aws-sdk-ecr (~> 1.5)
       bundler (>= 1.16, < 3.0.0)
       commonmarker (>= 0.20.1, < 0.24.0)
-      docker_registry2 (~> 1.14.0)
+      docker_registry2 (~> 1.18.0)
       excon (~> 0.96, < 0.101)
       faraday (= 2.7.4)
       faraday-retry (= 2.2.0)
@@ -150,7 +150,7 @@ GEM
       irb (>= 1.5.0)
       reline (>= 0.3.1)
     diff-lcs (1.5.0)
-    docker_registry2 (1.14.0)
+    docker_registry2 (1.18.0)
       rest-client (>= 1.8.0)
     domain_name (0.5.20190701)
       unf (>= 0.0.5, < 1.0.0)