upgrading from osmosis-std-derive = "0.15.3" to 0.20.1 - CosmwasmExt - shim not found

[PFC-developer]

Hi!

I'm this package to parse the proto files for tokenfactory and v0.15.3 works great.

but v0.20.1 (actually anything beyond 0.15.3) fails with the following issue

error[E0433]: failed to resolve: could not find `shim` in the crate root
  --> packages/pfc-treasurechest/src/tf/cosmos/denom.rs:22:5
   |
22 |     CosmwasmExt,
   |     ^^^^^^^^^^^ could not find `shim` in the crate root
   |
   = note: this error originates in the derive macro `CosmwasmExt` (in Nightly builds, run with -Z macro-backtrace for more info)

I was wondering if you had seen this before, and how I can upgrade to the later version

[iboss-ptk]

wasn't intended for the derived to be used as a standalone in the first place so I didn't take care of that but this should be the cause

PR is welcome, my suggestion is feature flag it, make it osmosis-std-only or something along that line.

Or else, for a quick hack, you can copy paste this into your crate::shim.