Import Grant model used in townsquare utils

[apbendi]

Description

When logged in and visiting the Grant Details page, the backend is throwing an error due to a missing import. This PR adds the import needed.

[codecov]

Codecov Report

Merging #6691 into master will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #6691      +/-   ##
==========================================
+ Coverage   27.12%   27.14%   +0.02%     
==========================================
  Files         291      291              
  Lines       27115    27116       +1     
  Branches     3989     3989              
==========================================
+ Hits         7354     7361       +7     
+ Misses      19493    19487       -6     
  Partials      268      268              

Impacted Files	Coverage Δ
app/townsquare/utils.py	18.18% <100.00%> (+2.55%)	⬆️
app/dashboard/embed.py	31.60% <0.00%> (+3.44%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 7df6d5a...888579b. Read the comment docs.

[thelostone-mc]

@apbendi Oh we just got this in via #6693 😅
Thanks for the PR though <3