build: enable `yarn` and `pnpm` Corepack binaries by default

Fixes: https://github.com/nodejs/node/issues/50963

Last version of Corepack has addressed (some of) the major concerns that was discussed in the TSC meeting last time:

• https://github.com/nodejs/corepack/pull/360
• https://github.com/nodejs/corepack/pull/364

IMO having Corepack enabled by default will overall be a clear win for Yarn and PNPM users (and won't affect npm users). Having it enabled by default does not stop those who don't like the "jumper binary" pattern to install Yarn and PNPM as they see fit.