Merge pull request #2681 from tnull/2023-10-bump-msrv-to-1.63.0

Bump MSRV to rustc 1.63.0

diff --cc lightning/src/ln/channel.rs
Simple merge

diff --cc lightning/src/ln/channelmanager.rs
Simple merge

diff --cc lightning/src/ln/payment_tests.rs
Simple merge

diff --cc lightning/src/util/test_utils.rs
Simple merge