Use single (cached) build for tests & release

[carlcsaposs-canonical]

Use the same build for integration tests & release, so that we release what we tested
Use charmcraftcache for the build

Signed by Mykola & Jon: https://docs.google.com/document/d/1Wt0ds4dEcih4cvHWkbvvALtqonC_D9crcNQteX34SUg/edit

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 75.53%. Comparing base (1cc4d7e) to head (08746e4).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #825      +/-   ##
==========================================
- Coverage   75.54%   75.53%   -0.01%     
==========================================
  Files          12       12              
  Lines        3112     3115       +3     
  Branches      465      466       +1     
==========================================
+ Hits         2351     2353       +2     
  Misses        621      621              
- Partials      140      141       +1     

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