rust源使用sparse

[source.crates-io]
# To use sparse index, change 'rsproxy' to 'rsproxy-sparse'
replace-with = 'rsproxy-sparse'

[source.rsproxy]
registry = "https://rsproxy.cn/crates.io-index"
[source.rsproxy-sparse]
registry = "sparse+https://rsproxy.cn/index/"

[registries.rsproxy]
index = "https://rsproxy.cn/crates.io-index"

[net]
git-fetch-with-cli = true
[unstable]
sparse-registry = true