Fix AcceptListGrpcQuerier concurrency issues

[pinosu]

Resolves #2051

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 42.98%. Comparing base (c2b31e0) to head (00f9840).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
x/wasm/keeper/query_plugins.go	50.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2065      +/-   ##
==========================================
+ Coverage   42.85%   42.98%   +0.12%     
==========================================
  Files          85       85              
  Lines       11587    11589       +2     
==========================================
+ Hits         4966     4981      +15     
+ Misses       6180     6162      -18     
- Partials      441      446       +5     

Files with missing lines	Coverage Δ
x/wasm/keeper/query_plugins.go	59.05% <50.00%> (+2.73%)	⬆️

[chipshort]

LGTM, nice work