v4.0.0-rc2

This is the second release candidate for the first official release of Lean 4.

It replaces v4.0.0-rc1 as we decided that the experimental build/lake.lock behaviour was too disruptive to users, and temporarily removed it.

What's Changed

• doc: fix mid priority doc comment by @digama0 in #2440
• doc: fix typo in Lake's Require DSL by @ConnorBaker in #2439
• chore: add PULL_REQUEST_TEMPLATE.md by @semorrison in #2443
• fix: include moreLinkArgs in precompile link by @tydeu in #2447
• feat: lake env w/o configuration + more by @tydeu in #2428
• chore: disable lake.lock (for now) by @tydeu in #2445

Full Changelog: v4.0.0-rc1...v4.0.0-rc2