chore: add publish script for 7.x

Author: vkarpov15

package.json

@@ -108,6 +108,7 @@
     "release-5x": "git pull origin 5.x && git push origin 5.x && git push origin 5.x --tags && npm publish --tag 5x",
     "release-6x": "git pull origin 6.x && git push origin 6.x && git push origin 6.x --tags && npm publish --tag 6x",
     "mongo": "node ./tools/repl.js",
+    "publish-7x": "npm publish --tag 7x",
     "test": "mocha --exit ./test/*.test.js",
     "test-deno": "deno run --allow-env --allow-read --allow-net --allow-run --allow-sys --allow-write ./test/deno.js",
     "test-rs": "START_REPLICA_SET=1 mocha --timeout 30000 --exit ./test/*.test.js",