Bump borsh to v1

[seanchen1991]

Bump the borsh dependency to v1 in order to address this security alert in ibc-rs: https://github.com/cosmos/ibc-rs/security/dependabot/1

[seanchen1991]

Hm, looks like there's an issue with a borsh dependency, toml_datetime:

error: failed to select a version for `toml_datetime`.
    ... required by package `toml_edit v0.21.0`
    ... which satisfies dependency `toml_edit = "^0.21.0"` of package `proc-macro-crate v3.0.0`
    ... which satisfies dependency `proc-macro-crate = "^3"` of package `borsh-derive v1.5.0`
    ... which satisfies dependency `borsh-derive = "~1.5.0"` of package `borsh v1.5.0`
    ... which satisfies dependency `borsh = "^1.5"` (locked to 1.5.0) of package `ibc-proto v0.44.0 (/Users/seanchen/Informal/ibc-proto-rs)`
versions that meet the requirements `^0.6.5` are: 0.6.5

all possible versions conflict with previously selected packages.

I'm not sure what needs to be updated in order to address this dependency mismatch.