Fix destruction of projects with pipelines

If a repository were deleted, the Gitaly implementation of
list_commits_by_oid would catch a GRPC NotFound error and simply return
an empty set.

However, the Rugged implementation would throw an NoRepository
exception. This would prevent a repository from being deleted.

We make the Rugged implementation consistent with Gitaly since the
behavior of destroying projects and CI pipelines relies on the Gitaly
implementation.

Relates to https://gitlab.com/gitlab-org/gitlab/-/issues/349414

Changelog: fixed

lib/gitlab/git/rugged_impl/commit.rb

@@ -31,6 +31,9 @@ module Gitlab
             oids.map { |oid| rugged_find(repo, oid) }
               .compact
               .map { |commit| decorate(repo, commit) }
+          # Match Gitaly's list_commits_by_oid behavior
+          rescue ::Gitlab::Git::Repository::NoRepository
+            []
           end
 
           override :find_commit

spec/lib/gitlab/git/commit_spec.rb

@@ -486,6 +486,16 @@ RSpec.describe Gitlab::Git::Commit, :seed_helper do
           expect(commits.first.sha).to eq(SeedRepo::Commit::ID)
           expect(commits.second.sha).to eq(SeedRepo::FirstCommit::ID)
         end
+
+        context 'when repo does not exist' do
+          let(:no_repository) { Gitlab::Git::Repository.new('default', '@does-not-exist/project', '', 'bogus/project') }
+
+          it 'returns empty commits' do
+            commits = described_class.batch_by_oid(no_repository, oids)
+
+            expect(commits.count).to eq(0)
+          end
+        end
       end
 
       context 'when oids is empty' do