Fix GitHub Package Repository publishing

Author: Robert Clark

.github/workflows/release.yml

@@ -26,8 +26,10 @@ jobs:
           gem push *.gem
         env:
           GEM_HOST_API_KEY: ${{secrets.RUBYGEMS_AUTH_TOKEN}}
-      - name: Publish to GitHub
-        uses: jstastny/publish-gem-to-github@master
-        with:
-          token: ${{ secrets.GITHUB_TOKEN }}
-          owner: mitre
+      - name: Publish to GPR
+        run: |
+          printf -- "---\n:github: Bearer ${GEM_HOST_API_KEY}\n" > $HOME/.gem/credentials
+          gem push --KEY github --host https://rubygems.pkg.github.com/${OWNER} *.gem
+        env:
+          GEM_HOST_API_KEY: ${{ secrets.GITHUB_TOKEN }}
+          OWNER: mitre