fix(deps): use only Vault API submodule

[ecrupper]

As the library states here, we really should only be pulling in the API submodule. This really cleans up our dependencies and leverages Docker test clusters for our existing testing.

This also should reduce dependabot noise in general.

One thing of note, the tests do take a fair deal longer to run, so the testing timeout option may need adjusting in your setup.

[codecov]

Codecov Report

Attention: Patch coverage is 92.85714% with 1 line in your changes missing coverage. Please review.

Project coverage is 45.62%. Comparing base (479673e) to head (96d8d48).
Report is 1 commits behind head on main.

Files	Patch %	Lines
vault/vault.go	92.85%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #460      +/-   ##
==========================================
+ Coverage   44.60%   45.62%   +1.02%     
==========================================
  Files           7        7              
  Lines         213      217       +4     
==========================================
+ Hits           95       99       +4     
  Misses        103      103              
  Partials       15       15              

Files	Coverage Δ
vault/vault.go	59.57% <92.85%> (+3.76%)	⬆️