v31.1
tidy: remove deprecated header
test: Format strings in `*.rs`
iwyu: Document mappings for libc symbols
contrib: remove copyright_header.py
build, wallet, doc: Remove BDB
refactor: [move-only] Merge core_io module
contrib: Remove confusing and redundant encoding from IO
scripted-diff: [doc] Unify stale copyright headers
kernel: Update headerssync params
gitian: Improve error handling