chore(internal): support pre-release versioning (#270)

Author: stainless-bot

release-please-config.json

@@ -6,6 +6,8 @@
   "$schema": "https://raw.githubusercontent.com/stainless-api/release-please/main/schemas/config.json",
   "include-v-in-tag": true,
   "include-component-in-tag": true,
+  "versioning": "prerelease",
+  "prerelease": true,
   "bump-minor-pre-major": true,
   "bump-patch-for-minor-pre-major": false,
   "pull-request-header": "Automated Release PR",