Fix deprecated package report in weekly automation

[jeremymeng]

we are using output of rush update to log issues for deprecated packages. After moving to pnpm, we may or may need to tweak it to work again.

[jeremymeng]

Now that we move pnpm, it may be possible to enable dependabot

[jeremymeng]

#35763

We have isDeprecated from pnpm outdated output