[Fix] Bump chrono to 0.4.27

[CyberHoward]

Bumps chrono dependency of osmosis-std to v0.4.27 because >=v0.4.27 is incompatible with lower versions, causing our builds to fail:

error[E0599]: no function or associated item named `from_naive_utc_and_offset` found for struct `DateTime` in the current scope
  --> packages/osmosis-std/src/shim.rs:39:43
   |
39 |         let dt: DateTime<Utc> = DateTime::from_naive_utc_and_offset(dt, Utc);
   |                                           ^^^^^^^^^^^^^^^^^^^^^^^^^ function or associated item not found in `DateTime<_>`