Our 1.63 build on Ubuntu has been failing for quite some time
because it runs out of disk space trying to build tests in the last
cfg-flag steps. Thus, we add a few new `cargo clean`s here to fix
it.
echo -e "\n\nTest cfg-flag builds"
RUSTFLAGS="--cfg=taproot" cargo test --verbose --color always -p lightning
+[ "$CI_MINIMIZE_DISK_USAGE" != "" ] && cargo clean
RUSTFLAGS="--cfg=async_signing" cargo test --verbose --color always -p lightning
+[ "$CI_MINIMIZE_DISK_USAGE" != "" ] && cargo clean
RUSTFLAGS="--cfg=dual_funding" cargo test --verbose --color always -p lightning