As we now require `rustfmt` pass on a subset of our files, its
helpful to have a script which will automatically format any
required files so that contributors don't need to think too hard
about it.
This breaks backwards compatibility with versions of LDK prior to
0.0.113 as they expect to always read signer data.
This also substantially reduces allocations during `ChannelManager`
serialization, as we currently don't pre-allocate the `Vec` that
the signer gets written in to. We could alternatively pre-allocate
that `Vec`, but we've been set up to skip the write entirely for a
while, and 0.0.113 was released nearly a year ago. Users
downgrading to LDK 0.0.112 and before at this point should not be
expected.
1.41.1 is currently the Firefox ESR MSRV, which means its also the
version several Linux distros ship. Further, rust-bitcoin is likely
to make a similar change soon, see
https://github.com/rust-bitcoin/rust-bitcoin/issues/510.
We wanted to bump to 1.29 to continue to support mrustc bootstrapping, but on 1.29
there's a bug preventing us from compiling the lightning package only, thus parts
of lightning-net-tokio cause a compilation error.
The advantage of bumping the MSRV is an improved borrow checker which should
enable improved code quality, and not having jump through weird hoops sometimes
to get 1.22 working.
