Statically validate connector config during dry-run.

[sudiptob2]

Description

As described in #8721, the current validate command cannot capture improper connector usage errors during a dry run.

One proposed solution (as mentioned in this comment) is to surface configuration errors by instantiating the service during the dry run. However, reviewers preferred statically verifying the errors over instantiating the service (see the PR #12488 comments).

The validation logic for connectors is located in the service/internal/graph package. In the discussion of PR #12681, it was concluded that instantiating the graph is the better approach (see this comment).

Finally, this PR uses the graph.Build() method to surface configuration errors during the dry run.

Link to tracking issue

Fixes #8721

Testing

Documentation

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.55%. Comparing base (622ce90) to head (92d543e).

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #12712      +/-   ##
==========================================
+ Coverage   91.53%   91.55%   +0.01%     
==========================================
  Files         483      483              
  Lines       26453    26488      +35     
==========================================
+ Hits        24215    24250      +35     
  Misses       1772     1772              
  Partials      466      466              

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[sudiptob2]

cc: @djaglowski @mx-psi