Update tuf conformance

Author: segiddins

.github/workflows/ci.yml

@@ -58,6 +58,11 @@ jobs:
           environment: staging
           skip-signing: true
         if: ${{ matrix.os }} == "ubuntu-latest"
+      - name: Run the TUF conformance tests
+        uses: theupdateframework/tuf-conformance@649423d80c91dd5f803b7bbe691d9e2b304b1384
+        with:
+          entrypoint: ${{ github.workspace }}/bin/tuf-conformance-entrypoint
+        if: ${{ matrix.os }} == "ubuntu-latest"
       - name: Upload coverage reports to Codecov
         uses: codecov/codecov-action@e28ff129e5465c2c0dcc6f003fc735cb6ae0c673 # v4.5.0
         if: ${{ matrix.ruby }} == ${{ fromJson(needs.ruby-versions.outputs.latest) }} && ${{ matrix.os }} == "ubuntu-latest" && always()

Rakefile

@@ -130,7 +130,7 @@ end
 GitRepo.define_task(:tuf_conformance).tap do |task|
   task.path = "test/tuf-conformance"
   task.url = "https://github.com/theupdateframework/tuf-conformance.git"
-  task.commit = "refs/pull/99/head"
+  task.commit = "649423d80c91dd5f803b7bbe691d9e2b304b1384"
 end
 
 namespace :tuf_conformance do

lib/sigstore/tuf/updater.rb

@@ -168,7 +168,7 @@ def load_targets(role, parent_role)
         @trusted_set.update_delegated_targets(data, role, parent_role).tap do
           logger.debug { "Loaded targets for #{role} from local metadata" }
         end
-      rescue Errno::ENOENT, Error::MetaVersionHigher, Error::MetaVersionLower => e
+      rescue Errno::ENOENT, Error::MetaVersionHigher, Error::MetaVersionLower, Error::TooFewSignatures => e
         logger.debug { "No local targets for #{role}, fetching: #{e.class} #{e.message}" }
 
         snapshot = @trusted_set.snapshot