test(bdd): fail Go BDD runner on undefined steps

[seokjin0414]

Follow-up to #3554 — Go half of #3634 (Rust half in #3680).

godog is non-strict by default and neither godog.Options block set Strict, so a step without a matching definition in the Go runner is reported as undefined while go test still exits 0 and CI stays green. Both suites now set Strict: true; the existing s.Run() != 0 check turns that into a test failure.

Verification (local server with --with-default-root-credentials, fresh data dir per run):

• green path: BDD_FEATURE=basic_messaging go test -count=1 ./tests/ → exit 0, 17 steps (17 passed)
• red path (repro from BDD: rust and go runners pass silently on undefined steps #3634: bogus step appended to the feature): exit 1, 1 scenarios (1 undefined) → FAIL
• gofmt / go vet clean

Refs #3634

[github-actions]

Thanks for the PR. It is labeled S-waiting-on-review and queued for review.

Slash commands (own line, regular comment) move it around the queue:

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 73.99%. Comparing base (6f1d548) to head (da1d7b4).

Additional details and impacted files

@@            Coverage Diff            @@
##             master    #3681   +/-   ##
=========================================
  Coverage     73.99%   73.99%           
  Complexity      937      937           
=========================================
  Files          1301     1301           
  Lines        147393   147393           
  Branches     122945   122945           
=========================================
  Hits         109063   109063           
  Misses        34858    34858           
  Partials       3472     3472           

Components	Coverage Δ
Rust Core	74.29% <ø> (ø)
Java SDK	62.44% <ø> (ø)
C# SDK	72.18% <ø> (ø)
Python SDK	92.17% <ø> (ø)
PHP SDK	84.29% <ø> (ø)
Node SDK	91.26% <ø> (ø)
Go SDK	42.87% <ø> (ø)

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[seokjin0414]

@hubcio could you take a look at this one as well? go half of #3634, same fix as the rust one (#3680) you approved — 2-line diff. CI is re-running after a rebase onto latest master.