chore: Fix artifact download (#313)

Author: keelerm84

.github/actions/publish/action.yml

@@ -15,6 +15,7 @@ runs:
     - uses: actions/download-artifact@v4
       with:
         pattern: 'gems-*'
+        merge-multiple: true
 
     - name: Hash gem for provenance
       id: gem-hash

.github/workflows/manual-publish.yml

@@ -39,6 +39,7 @@ jobs:
 
       - uses: launchdarkly/gh-actions/actions/release-secrets@release-secrets-v1.2.0
         name: 'Get rubygems API key'
+        if: ${{ !inputs.dry_run }}
         with:
           aws_assume_role: ${{ vars.AWS_ROLE_ARN }}
           ssm_parameter_pairs: '/production/common/releasing/rubygems/api_key = GEM_HOST_API_KEY'