Chipyard 1.12.2

Added

• Update Initial-Repo-Setup.rst (by @abejgonzalez in #1977)
• Add FireSim paper tests (migrating them from FireSim) (by @abejgonzalez in #1980)
• Integrate Ara vector unit (by @jerryz123 in #1973)

Changed

• Add hook into Chipyard build system for FireSim (by @abejgonzalez in #1935)

Fixed

• Bump constellation to fix support for AXI-converted TL (by @jerryz123 in #1976)
• Update generate-conda-lockfiles.sh (by @abejgonzalez in #1978)
• Bump Checkpointing Script + Docs (by @abejgonzalez in #1911)

Full Changelog: 1.12.1...1.12.2