[rush] "Unknown project config" warnings appear during `rush install` after upgrading to 5.166.0

[kgetz-arista]

Summary

New warnings are appearing during rush install.

Repro steps

rush install

Expected result: No warnings

Actual result: These warnings appear now:

13:54:04  Running "npm install" in /home/jenkins/.rush/node-v24.12.0/pnpm-10.14.0
13:54:05  npm warn Unknown project config "email". This will stop working in the next major version of npm.
13:54:05  npm warn Unknown project config "publish-branch". This will stop working in the next major version of npm.

Details

Started after upgrading to 5.166.0.

Standard questions

Please answer these questions to help us investigate your issue more quickly:

Question	Answer
@microsoft/rush globally installed version?	5.166.0
rushVersion from rush.json?	5.166.0
pnpmVersion, npmVersion, or yarnVersion from rush.json?	10.14.0
Operating system?	Linux (Debian)
Would you consider contributing a PR?	No
Node.js version (node -v)?	24.12.0

[iclanton]

When syncing the .npmrc from common/config/rush, we don't filter out properties that npm doesn't understand. We already filter out lines that mention env vars that aren't currently defined, so filtering out properties that npm doesn't support should be a simple enough change. However, I have seen this with auth token properties, so we'll need to figure out how to handle that.