.github/workflows: further parameterize

If anyone else wants to re-use this code, this'll make it easier
to copy/paste.
diff --git a/.github/workflows/queue-main.yml b/.github/workflows/queue-main.yml
index b3201af..ade8791 100644
--- a/.github/workflows/queue-main.yml
+++ b/.github/workflows/queue-main.yml
@@ -51,6 +51,6 @@
             COMMIT_TO_PUSH="${{ needs.formatting.outputs.commit_sha }}"
           fi
 
-          git push https://${GITHUB_ACTOR}:${GITHUB_TOKEN}@github.com/boldsoftware/sketch.git "${COMMIT_TO_PUSH}":main
+          git push https://${GITHUB_ACTOR}:${GITHUB_TOKEN}@github.com/${GITHUB_REPOSITORY}.git "${COMMIT_TO_PUSH}":main
         env:
           GITHUB_TOKEN: ${{ github.token }}